Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals

ABSTRACT

A method and an apparatus for transmitting broadcast signals thereof are disclosed. The method for transmitting broadcast signals includes encoding DP data according to a code rate, wherein the encoding further includes LDPC encoding the DP data according to the code rate, bit interleaving the LDPC encoded DP data, mapping the bit interleaved DP data onto constellations, MIMO (Multi Input Multi Output) encoding the mapped DP data, and time interleaving the MIMO encoded DP data; building at least one signal frame by arranging the encoded DP data; and modulating data in the built signal frame by OFDM method and transmitting the broadcast signals having the modulated data, wherein the step of modulating includes inserting CPs in the built signal frame based on a CP set which includes information about locations of CPs, wherein the CP set is defined based on FFT size.

This application claims the benefit of U.S. Provisional PatentApplication No. 61/837,131 filed on Jun. 19, 2013 and U.S. ProvisionalPatent Application No. 61/847,534 filed on Jul. 17, 2013 which is herebyincorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for transmitting broadcastsignals, an apparatus for receiving broadcast signals and methods fortransmitting and receiving broadcast signals.

2. Discussion of the Related Art

As analog broadcast signal transmission comes to an end, varioustechnologies for transmitting/receiving digital broadcast signals arebeing developed. A digital broadcast signal may include a larger amountof video/audio data than an analog broadcast signal and further includevarious types of additional data in addition to the video/audio data.

That is, a digital broadcast system can provide HD (high definition)images, multi-channel audio and various additional services. However,data transmission efficiency for transmission of large amounts of data,robustness of transmission/reception networks and network flexibility inconsideration of mobile reception equipment need to be improved fordigital broadcast.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an apparatus fortransmitting broadcast signals and an apparatus for receiving broadcastsignals for future broadcast services and methods for transmitting andreceiving broadcast signals for future broadcast services.

An object of the present invention devised to solve the problem lies onan apparatus and method for transmitting broadcast signals to multiplexdata of a broadcast transmission/reception system providing two or moredifferent broadcast services in a time domain and transmit themultiplexed data through the same RF signal bandwidth and an apparatusand method for receiving broadcast signals corresponding thereto.

Another object of the present invention devised to solve the problemlies on an apparatus for transmitting broadcast signals, an apparatusfor receiving broadcast signals and methods for transmitting andreceiving broadcast signals to classify data corresponding to servicesby components, transmit data corresponding to each component as a datapipe, receive and process the data

Another object of the present invention devised to solve the problemlies on an apparatus for transmitting broadcast signals, an apparatusfor receiving broadcast signals and methods for transmitting andreceiving broadcast signals to signal signaling information necessary toprovide broadcast signals.

The object of the present invention can be achieved by providing amethod of transmitting broadcast signals including encoding DP (DataPipe) data according to a code rate, wherein the encoding furtherincludes LDPC (Low Density Parity Check) encoding the DP data accordingto the code rate, bit interleaving the LDPC encoded DP data, mapping thebit interleaved DP data onto constellations, MIMO (Multi Input MultiOutput) encoding the mapped DP data, and time interleaving the MIMOencoded DP data; building at least one signal frame by arranging theencoded DP data; and modulating data in the built signal frame by OFDM(Orthogonal Frequency Division Multiplexing) method and transmitting thebroadcast signals having the modulated data, wherein the step ofmodulating includes inserting CPs (Continual Pilots) in the built signalframe based on a CP set which includes information about locations ofCPs, wherein the CP set is defined based on FFT (Fast Fourier Transform)size.

Preferably, the CP set includes a common CP set and an additional CPset.

Preferably, the information about locations of CPs in the common CP setdefined based on 32K FFT size includes the information about locationsof CPs in the common CP set defined based on 16K FFT size.

Preferably, the common CP set includes information about locations ofnon SP (Scattered Pilot) bearing CPs, and wherein the additional CP setincludes information about locations of SP bearing CPs.

Preferably, the common CP set defined based on 32K FFT size includes afirst sub-set, a second sub-set, a third sub-set and a fourth sub-set,wherein the third sub-set is generated by inverting the first sub-setand shifting the inverted first sub-set, wherein the fourth sub-set isgenerated by inverting the second sub-set and shifting the invertedsecond sub-set.

In another aspect of the present invention, provided herein is an methodof receiving broadcast signals including receiving the broadcast signalshaving at least one signal frame and demodulating data in the at leastone signal frame by OFDM (Orthogonal Frequency Division Multiplexing)method; parsing the at least one signal frame by demapping DP (DataPipe) data; and decoding the DP data, wherein the decoding furtherincludes time deinterleaving the DP data, MIMO (Multi Input MultiOutput) decoding the time deinterleaved DP data, demapping the MIMOdecoded DP data from constellations, bit deinterleaving the demapped DPdata, and LDPC (Low Density Parity Check) decoding the bit deinterleavedDP data, wherein the step of demodulating includes obtaining CPs(Continual Pilots) in the at least one signal frame, wherein the CPs arelocated based on a CP set which includes information about locations ofCPs, wherein the CP set is defined based on FFT (Fast Fourier Transform)size.

Preferably, the CP set includes a common CP set and an additional CPset.

Preferably, the information about locations of CPs in the common CP setdefined based on 32K FFT size includes the information about locationsof CPs in the common CP set defined based on 16K FFT size.

Preferably, the common CP set includes information about locations ofnon SP (Scattered Pilot) bearing CPs, and wherein the additional CP setincludes information about locations of SP bearing CPs.

Preferably, the common CP set defined based on 32K FFT size includes afirst sub-set, a second sub-set, a third sub-set and a fourth sub-set,wherein the third sub-set is generated by inverting the first sub-setand shifting the inverted first sub-set, wherein the fourth sub-set isgenerated by inverting the second sub-set and shifting the invertedsecond sub-set.

In another aspect of the present invention, provided herein is anapparatus for transmitting broadcast signals including an encodingmodule configured to encode DP (Data Pipe) data according to a coderate, wherein the encoding module further includes a LDPC (Low DensityParity Check) encoding module configured to LDPC encode the DP dataaccording to the code rate, a bit interleaving module configured to bitinterleave the LDPC encoded DP data, a mapping module configured to mapthe bit interleaved DP data onto constellations, a MIMO (Multi InputMulti Output) encoding module configured to MIMO encode the mapped DPdata, and a time interleaving module configured to time interleave theMIMO encoded DP data; a frame building module configured to build atleast one signal frame by arranging the encoded DP data; and an OFDM(Orthogonal Frequency Division Multiplexing) module configured tomodulate data in the built signal frame by OFDM method and transmit thebroadcast signals having the modulated data, wherein the OFDM modulefurther configured to insert CPs (Continual Pilots) in the built signalframe based on a CP set which includes information about locations ofCPs, wherein the CP set is defined based on FFT (Fast Fourier Transform)size.

Preferably, the CP set includes a common CP set and an additional CPset.

Preferably, the information about locations of CPs in the common CP setdefined based on 32K FFT size includes the information about locationsof CPs in the common CP set defined based on 16K FFT size.

Preferably, the common CP set includes information about locations ofnon SP (Scattered Pilot) bearing CPs, and wherein the additional CP setincludes information about locations of SP bearing CPs.

Preferably, the common CP set defined based on 32K FFT size includes afirst sub-set, a second sub-set, a third sub-set and a fourth sub-set,wherein the third sub-set is generated by inverting the first sub-setand shifting the inverted first sub-set, wherein the fourth sub-set isgenerated by inverting the second sub-set and shifting the the invertedsecond sub-set.

In another aspect of the present invention, provided herein is anapparatus for receiving broadcast signals including an OFDM (OrthogonalFrequency Division Multiplexing) module configured to receive thebroadcast signals having at least one signal frame and demodulate datain the at least one signal frame by OFDM method; a parsing moduleconfigured to parse the at least one signal frame by demapping DP (DataPipe) data; and a decoding module configured to decode the DP data,wherein the decoding module further includes a time deinterleavingmodule configured to time deinterleave the DP data, a MIMO (Multi InputMulti Output) decoding module configured to MIMO decode the timedeinterleaved DP data, a demapping module configured to demap the MIMOdecoded DP data from constellations, a bit deinterleaving moduleconfigured to bit deinterleave the demapped DP data, and a LDPC (LowDensity Parity Check) decoding module configured to LDPC decode the bitdeinterleaved DP data, wherein the OFDM module further configured toobtain CPs (Continual Pilots) in the at least one signal frame, whereinthe CPs are located based on a CP set which includes information aboutlocations of CPs, wherein the CP set is defined based on FFT (FastFourier Transform) size.

Preferably, the CP set includes a common CP set and an additional CPset.

Preferably, the information about locations of CPs in the common CP setdefined based on 32K FFT size includes the information about locationsof CPs in the common CP set defined based on 16K FFT size.

Preferably, the common CP set includes information about locations ofnon SP (Scattered Pilot) bearing CPs, and wherein the additional CP setincludes information about locations of SP bearing CPs.

Preferably, the common CP set defined based on 32K FFT size includes afirst sub-set, a second sub-set, a third sub-set and a fourth sub-set,wherein the third sub-set is generated by inverting the first sub-setand shifting the inverted first sub-set, wherein the fourth sub-set isgenerated by inverting the second sub-set and shifting the the invertedsecond sub-set.

The present invention can process data according to servicecharacteristics to control QoS for each service or service component,thereby providing various broadcast services.

The present invention can achieve transmission flexibility bytransmitting various broadcast services through the same RF signalbandwidth.

The present invention can improve data transmission efficiency andincrease robustness of transmission/reception of broadcast signals usinga MIMO system.

According to the present invention, it is possible to provide broadcastsignal transmission and reception methods and apparatus capable ofreceiving digital broadcast signals without error even with mobilereception equipment or in an indoor environment.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 illustrates a structure of an apparatus for transmittingbroadcast signals for future broadcast services according to anembodiment of the present invention.

FIG. 2 illustrates an input formatting module according to an embodimentof the present invention.

FIG. 3 illustrates an input formatting module according to anotherembodiment of the present invention.

FIG. 4 illustrates an input formatting module according to anotherembodiment of the present invention.

FIG. 5 illustrates a coding & modulation module according to anembodiment of the present invention.

FIG. 6 illustrates a frame structure module according to an embodimentof the present invention.

FIG. 7 illustrates a waveform generation module according to anembodiment of the present invention.

FIG. 8 illustrates a structure of an apparatus for receiving broadcastsignals for future broadcast services according to an embodiment of thepresent invention.

FIG. 9 illustrates a synchronization & demodulation module according toan embodiment of the present invention.

FIG. 10 illustrates a frame parsing module according to an embodiment ofthe present invention.

FIG. 11 illustrates a demapping & decoding module according to anembodiment of the present invention.

FIG. 12 illustrates an output processor according to an embodiment ofthe present invention.

FIG. 13 illustrates an output processor according to another embodimentof the present invention.

FIG. 14 illustrates a coding & modulation module according to anotherembodiment of the present invention.

FIG. 15 illustrates a demapping & decoding module according to anotherembodiment of the present invention.

FIG. 16 illustrates a waveform generation module and a synchronization &demodulation module according to another embodiment of the presentinvention.

FIG. 17 illustrates definition of a CP bearing SP and a CP not bearingSP according to an embodiment of the present invention.

FIG. 18 shows a reference index table according to an embodiment of thepresent invention.

FIG. 19 illustrates the concept of configuring a reference index tablein CP pattern generation method #1 using the position multiplexingmethod.

FIG. 20 illustrates a method for generating a reference index table inCP pattern generation method #1 using the position multiplexing methodaccording to an embodiment of the present invention.

FIG. 21 illustrates the concept of configuring a reference index tablein CP pattern generation method #2 using the position multiplexingmethod according to an embodiment of the present invention.

FIG. 22 illustrates a method for generating a reference index table inCP pattern generation method #2 using the position multiplexing method.

FIG. 23 illustrates a method for generating a reference index table inCP pattern generation method #3 using the position multiplexing methodaccording to an embodiment of the present invention.

FIG. 24 illustrates the concept of configuring a reference index tablein CP pattern generation method #1 using the pattern reversal method.

FIG. 25 illustrates a method for generating a reference index table inCP pattern generation method #1 using the pattern reversal methodaccording to an embodiment of the present invention.

FIG. 26 illustrates the concept of configuring a reference index tablein CP pattern generation method #2 using the pattern reversal methodaccording to an embodiment of the present invention.

FIG. 27 illustrates a method of transmitting broadcast signal accordingto an embodiment of the present invention.

FIG. 28 illustrates a method of receiving broadcast signal according toan embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The detailed description, which will be given below withreference to the accompanying drawings, is intended to explain exemplaryembodiments of the present invention, rather than to show the onlyembodiments that can be implemented according to the present invention.The following detailed description includes specific details in order toprovide a thorough understanding of the present invention. However, itwill be apparent to those skilled in the art that the present inventionmay be practiced without such specific details.

Although most terms used in the present invention have been selectedfrom general ones widely used in the art, some terms have beenarbitrarily selected by the applicant and their meanings are explainedin detail in the following description as needed. Thus, the presentinvention should be understood based upon the intended meanings of theterms rather than their simple names or meanings.

The present invention provides apparatuses and methods for transmittingand receiving broadcast signals for future broadcast services. Futurebroadcast services according to an embodiment of the present inventioninclude a terrestrial broadcast service, a mobile broadcast service, aUHDTV service, etc. The present invention may process broadcast signalsfor the future broadcast services through non-MIMO (Multiple InputMultiple Output) or MIMO according to one embodiment. A non-MIMO schemeaccording to an embodiment of the present invention may include a MISO(Multiple Input Single Output) scheme, a SISO (Single Input SingleOutput) scheme, etc.

While MISO or MIMO uses two antennas in the following for convenience ofdescription, the present invention is applicable to systems using two ormore antennas.

FIG. 1 illustrates a structure of an apparatus for transmittingbroadcast signals for future broadcast services according to anembodiment of the present invention.

The apparatus for transmitting broadcast signals for future broadcastservices according to an embodiment of the present invention can includean input formatting module 1000, a coding & modulation module 1100, aframe structure module 1200, a waveform generation module 1300 and asignaling generation module 1400. A description will be given of theoperation of each module of the apparatus for transmitting broadcastsignals.

Referring to FIG. 1, the apparatus for transmitting broadcast signalsfor future broadcast services according to an embodiment of the presentinvention can receive MPEG-TSs, IP streams (v4/v6) and generic streams(GSs) as an input signal. In addition, the apparatus for transmittingbroadcast signals can receive management information about theconfiguration of each stream constituting the input signal and generatea final physical layer signal with reference to the received managementinformation.

The input formatting module 1000 according to an embodiment of thepresent invention can classify the input streams on the basis of astandard for coding and modulation or services or service components andoutput the input streams as a plurality of logical data pipes (or datapipes or DP data). The data pipe is a logical channel in the physicallayer that carries service data or related metadata, which may carry oneor multiple service(s) or service component(s). In addition, datatransmitted through each data pipe may be called DP data.

In addition, the input formatting module 1000 according to an embodimentof the present invention can divide each data pipe into blocks necessaryto perform coding and modulation and carry out processes necessary toincrease transmission efficiency or to perform scheduling. Details ofoperations of the input formatting module 1000 will be described later.

The coding & modulation module 1100 according to an embodiment of thepresent invention can perform forward error correction (FEC) encoding oneach data pipe received from the input formatting module 1000 such thatan apparatus for receiving broadcast signals can correct an error thatmay be generated on a transmission channel. In addition, the coding &modulation module 1100 according to an embodiment of the presentinvention can convert FEC output bit data to symbol data and interleavethe symbol data to correct burst error caused by a channel. As shown inFIG. 1, the coding & modulation module 1100 according to an embodimentof the present invention can divide the processed data such that thedivided data can be output through data paths for respective antennaoutputs in order to transmit the data through two or more Tx antennas.

The frame structure module 1200 according to an embodiment of thepresent invention can map the data output from the coding & modulationmodule 1100 to signal frames. The frame structure module 1200 accordingto an embodiment of the present invention can perform mapping usingscheduling information output from the input formatting module 1000 andinterleave data in the signal frames in order to obtain additionaldiversity gain.

The waveform generation module 1300 according to an embodiment of thepresent invention can convert the signal frames output from the framestructure module 1200 into a signal for transmission. In this case, thewaveform generation module 1300 according to an embodiment of thepresent invention can insert a preamble signal (or preamble) into thesignal for detection of the transmission apparatus and insert areference signal for estimating a transmission channel to compensate fordistortion into the signal. In addition, the waveform generation module1300 according to an embodiment of the present invention can provide aguard interval and insert a specific sequence into the same in order tooffset the influence of channel delay spread due to multi-pathreception. Additionally, the waveform generation module 1300 accordingto an embodiment of the present invention can perform a procedurenecessary for efficient transmission in consideration of signalcharacteristics such as a peak-to-average power ratio of the outputsignal.

The signaling generation module 1400 according to an embodiment of thepresent invention generates final physical layer signaling informationusing the input management information and information generated by theinput formatting module 1000, coding & modulation module 1100 and framestructure module 1200. Accordingly, a reception apparatus according toan embodiment of the present invention can decode a received signal bydecoding the signaling information.

As described above, the apparatus for transmitting broadcast signals forfuture broadcast services according to one embodiment of the presentinvention can provide terrestrial broadcast service, mobile broadcastservice, UHDTV service, etc. Accordingly, the apparatus for transmittingbroadcast signals for future broadcast services according to oneembodiment of the present invention can multiplex signals for differentservices in the time domain and transmit the same.

FIGS. 2, 3 and 4 illustrate the input formatting module 1000 accordingto embodiments of the present invention. A description will be given ofeach figure.

FIG. 2 illustrates an input formatting module according to oneembodiment of the present invention. FIG. 2 shows an input formattingmodule when the input signal is a single input stream.

Referring to FIG. 2, the input formatting module according to oneembodiment of the present invention can include a mode adaptation module2000 and a stream adaptation module 2100.

As shown in FIG. 2, the mode adaptation module 2000 can include an inputinterface block 2010, a CRC-8 encoder block 2020 and a BB headerinsertion block 2030. Description will be given of each block of themode adaptation module 2000.

The input interface block 2010 can divide the single input stream inputthereto into data pieces each having the length of a baseband (BB) frameused for FEC (BCH/LDPC) which will be performed later and output thedata pieces.

The CRC-8 encoder block 2020 can perform CRC encoding on BB frame datato add redundancy data thereto.

The BB header insertion block 2030 can insert, into the BB frame data, aheader including information such as mode adaptation type (TS/GS/IP), auser packet length, a data field length, user packet sync byte, startaddress of user packet sync byte in data field, a high efficiency modeindicator, an input stream synchronization field, etc.

As shown in FIG. 2, the stream adaptation module 2100 can include apadding insertion block 2110 and a BB scrambler block 2120. Descriptionwill be given of each block of the stream adaptation module 2100.

If data received from the mode adaptation module 2000 has a lengthshorter than an input data length necessary for FEC encoding, thepadding insertion block 2110 can insert a padding bit into the data suchthat the data has the input data length and output the data includingthe padding bit.

The BB scrambler block 2120 can randomize the input bit stream byperforming an XOR operation on the input bit stream and a pseudo randombinary sequence (PRBS).

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

As shown in FIG. 2, the input formatting module can finally output datapipes to the coding & modulation module.

FIG. 3 illustrates an input formatting module according to anotherembodiment of the present invention. FIG. 3 shows a mode adaptationmodule 3000 of the input formatting module when the input signalcorresponds to multiple input streams.

The mode adaptation module 3000 of the input formatting module forprocessing the multiple input streams can independently process themultiple input streams.

Referring to FIG. 3, the mode adaptation module 3000 for respectivelyprocessing the multiple input streams can include input interfaceblocks, input stream synchronizer blocks 3100, compensating delay blocks3200, null packet deletion blocks 3300, CRC-8 encoder blocks and BBheader insertion blocks. Description will be given of each block of themode adaptation module 3000.

Operations of the input interface block, CRC-8 encoder block and BBheader insertion block correspond to those of the input interface block,CRC-8 encoder block and BB header insertion block described withreference to FIG. 2 and thus description thereof is omitted.

The input stream synchronizer block 3100 can transmit input stream clockreference (ISCR) information to generate timing information necessaryfor the apparatus for receiving broadcast signals to restore the TSs orGSs.

The compensating delay block 3200 can delay input data and output thedelayed input data such that the apparatus for receiving broadcastsignals can synchronize the input data if a delay is generated betweendata pipes according to processing of data including the timinginformation by the transmission apparatus.

The null packet deletion block 3300 can delete unnecessarily transmittedinput null packets from the input data, insert the number of deletednull packets into the input data based on positions in which the nullpackets are deleted and transmit the input data.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 4 illustrates an input formatting module according to anotherembodiment of the present invention.

Specifically, FIG. 4 illustrates a stream adaptation module of the inputformatting module when the input signal corresponds to multiple inputstreams.

The stream adaptation module of the input formatting module when theinput signal corresponds to multiple input streams can include ascheduler 4000, a 1-frame delay block 4100, an in-band signaling orpadding insertion block 4200, a physical layer signaling generationblock 4300 and a BB scrambler block 4400. Description will be given ofeach block of the stream adaptation module.

The scheduler 4000 can perform scheduling for a MIMO system usingmultiple antennas having dual polarity. In addition, the scheduler 4000can generate parameters for use in signal processing blocks for antennapaths, such as a bit-to-cell demux block, a cell interleaver block, atime interleaver block, etc. included in the coding & modulation moduleillustrated in FIG. 1.

The 1-frame delay block 4100 can delay the input data by onetransmission frame such that scheduling information about the next framecan be transmitted through the current frame for in-band signalinginformation to be inserted into the data pipes.

The in-band signaling or padding insertion block 4200 can insertundelayed physical layer signaling (PLS)-dynamic signaling informationinto the data delayed by one transmission frame. In this case, thein-band signaling or padding insertion block 4200 can insert a paddingbit when a space for padding is present or insert in-band signalinginformation into the padding space. In addition, the scheduler 4000 canoutput physical layer signaling-dynamic signaling information about thecurrent frame separately from in-band signaling information.Accordingly, a cell mapper, which will be described later, can map inputcells according to scheduling information output from the scheduler4000.

The physical layer signaling generation block 4300 can generate physicallayer signaling data which will be transmitted through a preamble symbolof a transmission frame or spread and transmitted through a data symbolother than the in-band signaling information. In this case, the physicallayer signaling data according to an embodiment of the present inventioncan be referred to as signaling information. Furthermore, the physicallayer signaling data according to an embodiment of the present inventioncan be divided into PLS-pre information and PLS-post information. ThePLS-pre information can include parameters necessary to encode thePLS-post information and static PLS signaling data and the PLS-postinformation can include parameters necessary to encode the data pipes.The parameters necessary to encode the data pipes can be classified intostatic PLS signaling data and dynamic PLS signaling data. The static PLSsignaling data is a parameter commonly applicable to all frames includedin a super-frame and can be changed on a super-frame basis. The dynamicPLS signaling data is a parameter differently applicable to respectiveframes included in a super-frame and can be changed on a frame-by-framebasis. Accordingly, the reception apparatus can acquire the PLS-postinformation by decoding the PLS-pre information and decode desired datapipes by decoding the PLS-post information.

The BB scrambler block 4400 can generate a pseudo-random binary sequence(PRBS) and perform an XOR operation on the PRBS and the input bitstreams to decrease the peak-to-average power ratio (PAPR) of the outputsignal of the waveform generation block. As shown in FIG. 4, scramblingof the BB scrambler block 4400 is applicable to both data pipes andphysical layer signaling information.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to designer.

As shown in FIG. 4, the stream adaptation module can finally output thedata pipes to the coding & modulation module.

FIG. 5 illustrates a coding & modulation module according to anembodiment of the present invention.

The coding & modulation module shown in FIG. 5 corresponds to anembodiment of the coding & modulation module illustrated in FIG. 1.

As described above, the apparatus for transmitting broadcast signals forfuture broadcast services according to an embodiment of the presentinvention can provide a terrestrial broadcast service, mobile broadcastservice, UHDTV service, etc.

Since QoS (quality of service) depends on characteristics of a serviceprovided by the apparatus for transmitting broadcast signals for futurebroadcast services according to an embodiment of the present invention,data corresponding to respective services needs to be processed throughdifferent schemes. Accordingly, the coding & modulation module accordingto an embodiment of the present invention can independently process datapipes input thereto by independently applying SISO, MISO and MIMOschemes to the data pipes respectively corresponding to data paths.Consequently, the apparatus for transmitting broadcast signals forfuture broadcast services according to an embodiment of the presentinvention can control QoS for each service or service componenttransmitted through each data pipe.

Accordingly, the coding & modulation module according to an embodimentof the present invention can include a first block 5000 for SISO, asecond block 5100 for MISO, a third block 5200 for MIMO and a fourthblock 5300 for processing the PLS-pre/PLS-post information. The coding &modulation module illustrated in FIG. 5 is an exemplary and may includeonly the first block 5000 and the fourth block 5300, the second block5100 and the fourth block 5300 or the third block 5200 and the fourthblock 5300 according to design. That is, the coding & modulation modulecan include blocks for processing data pipes equally or differentlyaccording to design.

A description will be given of each block of the coding & modulationmodule.

The first block 5000 processes an input data pipe according to SISO andcan include an FEC encoder block 5010, a bit interleaver block 5020, abit-to-cell demux block 5030, a constellation mapper block 5040, a cellinterleaver block 5050 and a time interleaver block 5060.

The FEC encoder block 5010 can perform BCH encoding and LDPC encoding onthe input data pipe to add redundancy thereto such that the receptionapparatus can correct an error generated on a transmission channel.

The bit interleaver block 5020 can interleave bit streams of theFEC-encoded data pipe according to an interleaving rule such that thebit streams have robustness against burst error that may be generated onthe transmission channel. Accordingly, when deep fading or erasure isapplied to QAM symbols, errors can be prevented from being generated inconsecutive bits from among all codeword bits since interleaved bits aremapped to the QAM symbols.

The bit-to-cell demux block 5030 can determine the order of input bitstreams such that each bit in an FEC block can be transmitted withappropriate robustness in consideration of both the order of input bitstreams and a constellation mapping rule.

In addition, the bit interleaver block 5020 is located between the FECencoder block 5010 and the constellation mapper block 5040 and canconnect output bits of LDPC encoding performed by the FEC encoder block5010 to bit positions having different reliability values and optimalvalues of the constellation mapper in consideration of LDPC decoding ofthe apparatus for receiving broadcast signals. Accordingly, thebit-to-cell demux block 5030 can be replaced by a block having a similaror equal function.

The constellation mapper block 5040 can map a bit word input thereto toone constellation. In this case, the constellation mapper block 5040 canadditionally perform rotation & Q-delay. That is, the constellationmapper block 5040 can rotate input constellations according to arotation angle, divide the constellations into an in-phase component anda quadrature-phase component and delay only the quadrature-phasecomponent by an arbitrary value. Then, the constellation mapper block5040 can remap the constellations to new constellations using a pairedin-phase component and quadrature-phase component.

In addition, the constellation mapper block 5040 can move constellationpoints on a two-dimensional plane in order to find optimal constellationpoints. Through this process, capacity of the coding & modulation module1100 can be optimized. Furthermore, the constellation mapper block 5040can perform the above-described operation using IQ-balancedconstellation points and rotation. The constellation mapper block 5040can be replaced by a block having a similar or equal function.

The cell interleaver block 5050 can randomly interleave cellscorresponding to one FEC block and output the interleaved cells suchthat cells corresponding to respective FEC blocks can be output indifferent orders.

The time interleaver block 5060 can interleave cells belonging to aplurality of FEC blocks and output the interleaved cells. Accordingly,the cells corresponding to the FEC blocks are dispersed and transmittedin a period corresponding to a time interleaving depth and thusdiversity gain can be obtained.

The second block 5100 processes an input data pipe according to MISO andcan include the FEC encoder block, bit interleaver block, bit-to-celldemux block, constellation mapper block, cell interleaver block and timeinterleaver block in the same manner as the first block 5000. However,the second block 5100 is distinguished from the first block 5000 in thatthe second block 5100 further includes a MISO processing block 5110. Thesecond block 5100 performs the same procedure including the inputoperation to the time interleaver operation as those of the first block5000 and thus description of the corresponding blocks is omitted.

The MISO processing block 5110 can encode input cells according to aMISO encoding matrix providing transmit diversity and outputMISO-processed data through two paths. MISO processing according to oneembodiment of the present invention can include OSTBC (orthogonal spacetime block coding)/OSFBC (orthogonal space frequency block coding,Alamouti coding).

The third block 5200 processes an input data pipe according to MIMO andcan include the FEC encoder block, bit interleaver block, bit-to-celldemux block, constellation mapper block, cell interleaver block and timeinterleaver block in the same manner as the second block 5100, as shownin FIG. 5. However, the data processing procedure of the third block5200 is different from that of the second block 5100 since the thirdblock 5200 includes a MIMO processing block 5220.

That is, in the third block 5200, basic roles of the FEC encoder blockand the bit interleaver block are identical to those of the first andsecond blocks 5000 and 5100 although functions thereof may be differentfrom those of the first and second blocks 5000 and 5100.

The bit-to-cell demux block 5210 can generate as many output bit streamsas input bit streams of MIMO processing and output the output bitstreams through MIMO paths for MIMO processing. In this case, thebit-to-cell demux block 5210 can be designed to optimize the decodingperformance of the reception apparatus in consideration ofcharacteristics of LDPC and MIMO processing.

Basic roles of the constellation mapper block, cell interleaver blockand time interleaver block are identical to those of the first andsecond blocks 5000 and 5100 although functions thereof may be differentfrom those of the first and second blocks 5000 and 5100. As shown inFIG. 5, as many constellation mapper blocks, cell interleaver blocks andtime interleaver blocks as the number of MIMO paths for MIMO processingcan be present. In this case, the constellation mapper blocks, cellinterleaver blocks and time interleaver blocks can operate equally orindependently for data input through the respective paths.

The MIMO processing block 5220 can perform MIMO processing on two inputcells using a MIMO encoding matrix and output the MIMO-processed datathrough two paths. The MIMO encoding matrix according to an embodimentof the present invention can include spatial multiplexing, Golden code,full-rate full diversity code, linear dispersion code, etc.

The fourth block 5300 processes the PLS-pre/PLS-post information and canperform SISO or MISO processing.

The basic roles of the bit interleaver block, bit-to-cell demux block,constellation mapper block, cell interleaver block, time interleaverblock and MISO processing block included in the fourth block 5300correspond to those of the second block 5100 although functions thereofmay be different from those of the second block 5100.

A shortened/punctured FEC encoder block 5310 included in the fourthblock 5300 can process PLS data using an FEC encoding scheme for a PLSpath provided for a case in which the length of input data is shorterthan a length necessary to perform FEC encoding. Specifically, theshortened/punctured FEC encoder block 5310 can perform BCH encoding oninput bit streams, pad 0s corresponding to a desired input bit streamlength necessary for normal LDPC encoding, carry out LDPC encoding andthen remove the padded 0s to puncture parity bits such that an effectivecode rate becomes equal to or lower than the data pipe rate.

The blocks included in the first block 5000 to fourth block 5300 may beomitted or replaced by blocks having similar or identical functionsaccording to design.

As illustrated in FIG. 5, the coding & modulation module can output thedata pipes (or DP data), PLS-pre information and PLS-post informationprocessed for the respective paths to the frame structure module.

FIG. 6 illustrates a frame structure module according to one embodimentof the present invention.

The frame structure module shown in FIG. 6 corresponds to an embodimentof the frame structure module 1200 illustrated in FIG. 1.

The frame structure module according to one embodiment of the presentinvention can include at least one cell-mapper 6000, at least one delaycompensation module 6100 and at least one block interleaver 6200. Thenumber of cell mappers 6000, delay compensation modules 6100 and blockinterleavers 6200 can be changed. A description will be given of eachmodule of the frame structure block.

The cell-mapper 6000 can allocate (or arrange) cells corresponding toSISO-, MISO- or MIMO-processed data pipes output from the coding &modulation module, cells corresponding to common data commonlyapplicable to the data pipes and cells corresponding to thePLS-pre/PLS-post information to signal frames according to schedulinginformation. The common data refers to signaling information commonlyapplied to all or some data pipes and can be transmitted through aspecific data pipe. The data pipe through which the common data istransmitted can be referred to as a common data pipe and can be changedaccording to design.

When the apparatus for transmitting broadcast signals according to anembodiment of the present invention uses two output antennas andAlamouti coding is used for MISO processing, the cell-mapper 6000 canperform pair-wise cell mapping in order to maintain orthogonalityaccording to Alamouti encoding. That is, the cell-mapper 6000 canprocess two consecutive cells of the input cells as one unit and map (orarrange) the unit to a frame. Accordingly, paired cells in an input pathcorresponding to an output path of each antenna can be allocated (orarranged) to neighboring positions in a transmission frame.

The delay compensation block 6100 can obtain PLS data corresponding tothe current transmission frame by delaying input PLS data cells for thenext transmission frame by one frame. In this case, the PLS datacorresponding to the current frame can be transmitted through a preamblepart in the current signal frame and PLS data corresponding to the nextsignal frame can be transmitted through a preamble part in the currentsignal frame or in-band signaling in each data pipe of the currentsignal frame. This can be changed by the designer.

The block interleaver 6200 can obtain additional diversity gain byinterleaving cells in a transport block corresponding to the unit of asignal frame. In addition, the block interleaver 6200 can performinterleaving by processing two consecutive cells of the input cells asone unit when the above-described pair-wise cell mapping is performed.Accordingly, cells output from the block interleaver 6200 can be twoconsecutive identical cells.

When pair-wise mapping and pair-wise interleaving are performed, atleast one cell mapper and at least one block interleaver can operateequally or independently for data input through the paths.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

As illustrated in FIG. 6, the frame structure module can output at leastone signal frame to the waveform generation module.

FIG. 7 illustrates a waveform generation module according to anembodiment of the present invention.

The waveform generation module illustrated in FIG. 7 corresponds to anembodiment of the waveform generation module 1300 described withreference to FIG. 1.

The waveform generation module according to an embodiment of the presentinvention can modulate and transmit as many signal frames as the numberof antennas for receiving and outputting signal frames output from theframe structure module illustrated in FIG. 6.

Specifically, the waveform generation module illustrated in FIG. 7 is anembodiment of a waveform generation module of an apparatus fortransmitting broadcast signals using m Tx antennas and can include mprocessing blocks for modulating and outputting frames corresponding tom paths. The m processing blocks can perform the same processingprocedure. A description will be given of operation of the firstprocessing block 7000 from among the m processing blocks.

The first processing block 7000 can include a reference signal & PAPRreduction block 7100, an inverse waveform transform block 7200, a PAPRreduction in time block 7300, a guard sequence insertion block 7400, apreamble insertion block 7500, a waveform processing block 7600, othersystem insertion block 7700 and a DAC (digital analog converter) block7800.

The reference signal insertion & PAPR reduction block 7100 can insert areference signal into a predetermined position of each signal block andapply a PAPR reduction scheme to reduce a PAPR in the time domain. If abroadcast transmission/reception system according to an embodiment ofthe present invention corresponds to an OFDM system, the referencesignal insertion & PAPR reduction block 7100 can use a method ofreserving some active subcarriers rather than using the same. Inaddition, the reference signal insertion & PAPR reduction block 7100 maynot use the PAPR reduction scheme as an optional feature according tobroadcast transmission/reception system.

The inverse waveform transform block 7200 can transform an input signalin a manner of improving transmission efficiency and flexibility inconsideration of transmission channel characteristics and systemarchitecture. If the broadcast transmission/reception system accordingto an embodiment of the present invention corresponds to an OFDM system,the inverse waveform transform block 7200 can employ a method oftransforming a frequency domain signal into a time domain signal throughinverse FFT operation. If the broadcast transmission/reception systemaccording to an embodiment of the present invention corresponds to asingle carrier system, the inverse waveform transform block 7200 may notbe used in the waveform generation module.

The PAPR reduction in time block 7300 can use a method for reducing PAPRof an input signal in the time domain. If the broadcasttransmission/reception system according to an embodiment of the presentinvention corresponds to an OFDM system, the PAPR reduction in timeblock 7300 may use a method of simply clipping peak amplitude.Furthermore, the PAPR reduction in time block 7300 may not be used inthe broadcast transmission/reception system according to an embodimentof the present invention since it is an optional feature.

The guard sequence insertion block 7400 can provide a guard intervalbetween neighboring signal blocks and insert a specific sequence intothe guard interval as necessary in order to minimize the influence ofdelay spread of a transmission channel. Accordingly, the receptionapparatus can easily perform synchronization or channel estimation. Ifthe broadcast transmission/reception system according to an embodimentof the present invention corresponds to an OFDM system, the guardsequence insertion block 7400 may insert a cyclic prefix into a guardinterval of an OFDM symbol.

The preamble insertion block 7500 can insert a signal of a known type(e.g. the preamble or preamble symbol) agreed upon between thetransmission apparatus and the reception apparatus into a transmissionsignal such that the reception apparatus can rapidly and efficientlydetect a target system signal. If the broadcast transmission/receptionsystem according to an embodiment of the present invention correspondsto an OFDM system, the preamble insertion block 7500 can define a signalframe composed of a plurality of OFDM symbols and insert a preamblesymbol into the beginning of each signal frame. That is, the preamblecarries basic PLS data and is located in the beginning of a signalframe.

The waveform processing block 7600 can perform waveform processing on aninput baseband signal such that the input baseband signal meets channeltransmission characteristics. The waveform processing block 7600 may usea method of performing square-root-raised cosine (SRRC) filtering toobtain a standard for out-of-band emission of a transmission signal. Ifthe broadcast transmission/reception system according to an embodimentof the present invention corresponds to a multi-carrier system, thewaveform processing block 7600 may not be used.

The other system insertion block 7700 can multiplex signals of aplurality of broadcast transmission/reception systems in the time domainsuch that data of two or more different broadcast transmission/receptionsystems providing broadcast services can be simultaneously transmittedin the same RF signal bandwidth. In this case, the two or more differentbroadcast transmission/reception systems refer to systems providingdifferent broadcast services. The different broadcast services may referto a terrestrial broadcast service, mobile broadcast service, etc. Datarelated to respective broadcast services can be transmitted throughdifferent frames.

The DAC block 7800 can convert an input digital signal into an analogsignal and output the analog signal. The signal output from the DACblock 7800 can be transmitted through m output antennas. A Tx antennaaccording to an embodiment of the present invention can have vertical orhorizontal polarity.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

FIG. 8 illustrates a structure of an apparatus for receiving broadcastsignals for future broadcast services according to an embodiment of thepresent invention.

The apparatus for receiving broadcast signals for future broadcastservices according to an embodiment of the present invention cancorrespond to the apparatus for transmitting broadcast signals forfuture broadcast services, described with reference to FIG. 1. Theapparatus for receiving broadcast signals for future broadcast servicesaccording to an embodiment of the present invention can include asynchronization & demodulation module 8000, a frame parsing module 8100,a demapping & decoding module 8200, an output processor 8300 and asignaling decoding module 8400. A description will be given of operationof each module of the apparatus for receiving broadcast signals.

The synchronization & demodulation module 8000 can receive input signalsthrough m Rx antennas, perform signal detection and synchronization withrespect to a system corresponding to the apparatus for receivingbroadcast signals and carry out demodulation corresponding to a reverseprocedure of the procedure performed by the apparatus for transmittingbroadcast signals.

The frame parsing module 8100 can parse input signal frames and extractdata through which a service selected by a user is transmitted. If theapparatus for transmitting broadcast signals performs interleaving, theframe parsing module 8100 can carry out deinterleaving corresponding toa reverse procedure of interleaving. In this case, the positions of asignal and data that need to be extracted can be obtained by decodingdata output from the signaling decoding module 8400 to restorescheduling information generated by the apparatus for transmittingbroadcast signals.

The demapping & decoding module 8200 can convert the input signals intobit domain data and then deinterleave the same as necessary. Thedemapping & decoding module 8200 can perform demapping for mappingapplied for transmission efficiency and correct an error generated on atransmission channel through decoding. In this case, the demapping &decoding module 8200 can obtain transmission parameters necessary fordemapping and decoding by decoding the data output from the signalingdecoding module 8400.

The output processor 8300 can perform reverse procedures of variouscompression/signal processing procedures which are applied by theapparatus for transmitting broadcast signals to improve transmissionefficiency. In this case, the output processor 8300 can acquirenecessary control information from data output from the signalingdecoding module 8400. The output of the output processor 8300corresponds to a signal input to the apparatus for transmittingbroadcast signals and may be MPEG-TSs, IP streams (v4 or v6) and genericstreams.

The signaling decoding module 8400 can obtain PLS information from thesignal demodulated by the synchronization & demodulation module 8000. Asdescribed above, the frame parsing module 8100, demapping & decodingmodule 8200 and output processor 8300 can execute functions thereofusing the data output from the signaling decoding module 8400.

FIG. 9 illustrates a synchronization & demodulation module according toan embodiment of the present invention.

The synchronization & demodulation module shown in FIG. 9 corresponds toan embodiment of the synchronization & demodulation module describedwith reference to FIG. 8. The synchronization & demodulation moduleshown in FIG. 9 can perform a reverse operation of the operation of thewaveform generation module illustrated in FIG. 7.

As shown in FIG. 9, the synchronization & demodulation module accordingto an embodiment of the present invention corresponds to asynchronization & demodulation module of an apparatus for receivingbroadcast signals using m Rx antennas and can include m processingblocks for demodulating signals respectively input through m paths. Them processing blocks can perform the same processing procedure. Adescription will be given of operation of the first processing block9000 from among the m processing blocks.

The first processing block 9000 can include a tuner 9100, an ADC block9200, a preamble detector 9300, a guard sequence detector 9400, awaveform transform block 9500, a time/frequency synchronization block9600, a reference signal detector 9700, a channel equalizer 9800 and aninverse waveform transform block 9900.

The tuner 9100 can select a desired frequency band, compensate for themagnitude of a received signal and output the compensated signal to theADC block 9200.

The ADC block 9200 can convert the signal output from the tuner 9100into a digital signal.

The preamble detector 9300 can detect a preamble (or preamble signal orpreamble symbol) in order to check whether or not the digital signal isa signal of the system corresponding to the apparatus for receivingbroadcast signals. In this case, the preamble detector 9300 can decodebasic transmission parameters received through the preamble.

The guard sequence detector 9400 can detect a guard sequence in thedigital signal. The time/frequency synchronization block 9600 canperform time/frequency synchronization using the detected guard sequenceand the channel equalizer 9800 can estimate a channel through areceived/restored sequence using the detected guard sequence.

The waveform transform block 9500 can perform a reverse operation ofinverse waveform transform when the apparatus for transmitting broadcastsignals has performed inverse waveform transform. When the broadcasttransmission/reception system according to one embodiment of the presentinvention is a multi-carrier system, the waveform transform block 9500can perform FFT. Furthermore, when the broadcast transmission/receptionsystem according to an embodiment of the present invention is a singlecarrier system, the waveform transform block 9500 may not be used if areceived time domain signal is processed in the frequency domain orprocessed in the time domain.

The time/frequency synchronization block 9600 can receive output data ofthe preamble detector 9300, guard sequence detector 9400 and referencesignal detector 9700 and perform time synchronization and carrierfrequency synchronization including guard sequence detection and blockwindow positioning on a detected signal. Here, the time/frequencysynchronization block 9600 can feed back the output signal of thewaveform transform block 9500 for frequency synchronization.

The reference signal detector 9700 can detect a received referencesignal. Accordingly, the apparatus for receiving broadcast signalsaccording to an embodiment of the present invention can performsynchronization or channel estimation.

The channel equalizer 9800 can estimate a transmission channel from eachTx antenna to each Rx antenna from the guard sequence or referencesignal and perform channel equalization for received data using theestimated channel.

The inverse waveform transform block 9900 may restore the originalreceived data domain when the waveform transform block 9500 performswaveform transform for efficient synchronization and channelestimation/equalization. If the broadcast transmission/reception systemaccording to an embodiment of the present invention is a single carriersystem, the waveform transform block 9500 can perform FFT in order tocarry out synchronization/channel estimation/equalization in thefrequency domain and the inverse waveform transform block 9900 canperform IFFT on the channel-equalized signal to restore transmitted datasymbols. If the broadcast transmission/reception system according to anembodiment of the present invention is a multi-carrier system, theinverse waveform transform block 9900 may not be used.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

FIG. 10 illustrates a frame parsing module according to an embodiment ofthe present invention.

The frame parsing module illustrated in FIG. 10 corresponds to anembodiment of the frame parsing module described with reference to FIG.8. The frame parsing module shown in FIG. 10 can perform a reverseoperation of the operation of the frame structure module illustrated inFIG. 6.

As shown in FIG. 10, the frame parsing module according to an embodimentof the present invention can include at least one block interleaver10000 and at least one cell demapper 10100.

The block interleaver 10000 can deinterleave data input through datapaths of the m Rx antennas and processed by the synchronization &demodulation module on a signal block basis. In this case, if theapparatus for transmitting broadcast signals performs pair-wiseinterleaving as illustrated in FIG. 8, the block interleaver 10000 canprocess two consecutive pieces of data as a pair for each input path.Accordingly, the block interleaver 10000 can output two consecutivepieces of data even when deinterleaving has been performed. Furthermore,the block interleaver 10000 can perform a reverse operation of theinterleaving operation performed by the apparatus for transmittingbroadcast signals to output data in the original order.

The cell demapper 10100 can extract cells corresponding to common data,cells corresponding to data pipes and cells corresponding to PLS datafrom received signal frames. The cell demapper 10100 can merge datadistributed and transmitted and output the same as a stream asnecessary. When two consecutive pieces of cell input data are processedas a pair and mapped in the apparatus for transmitting broadcastsignals, as shown in FIG. 6, the cell demapper 10100 can performpair-wise cell demapping for processing two consecutive input cells asone unit as a reverse procedure of the mapping operation of theapparatus for transmitting broadcast signals.

In addition, the cell demapper 10100 can extract PLS signaling datareceived through the current frame as PLS-pre & PLS-post data and outputthe PLS-pre & PLS-post data.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

FIG. 11 illustrates a demapping & decoding module according to anembodiment of the present invention.

The demapping & decoding module shown in FIG. 11 corresponds to anembodiment of the demapping & decoding module illustrated in FIG. 8. Thedemapping & decoding module shown in FIG. 11 can perform a reverseoperation of the operation of the coding & modulation module illustratedin FIG. 5.

The coding & modulation module of the apparatus for transmittingbroadcast signals according to an embodiment of the present inventioncan process input data pipes by independently applying SISO, MISO andMIMO thereto for respective paths, as described above. Accordingly, thedemapping & decoding module illustrated in FIG. 11 can include blocksfor processing data output from the frame parsing module according toSISO, MISO and MIMO in response to the apparatus for transmittingbroadcast signals.

As shown in FIG. 11, the demapping & decoding module according to anembodiment of the present invention can include a first block 11000 forSISO, a second block 11100 for MISO, a third block 11200 for MIMO and afourth block 11300 for processing the PLS-pre/PLS-post information. Thedemapping & decoding module shown in FIG. 11 is exemplary and mayinclude only the first block 11000 and the fourth block 11300, only thesecond block 11100 and the fourth block 11300 or only the third block11200 and the fourth block 11300 according to design. That is, thedemapping & decoding module can include blocks for processing data pipesequally or differently according to design.

A description will be given of each block of the demapping & decodingmodule.

The first block 11000 processes an input data pipe according to SISO andcan include a time deinterleaver block 11010, a cell deinterleaver block11020, a constellation demapper block 11030, a cell-to-bit mux block11040, a bit deinterleaver block 11050 and an FEC decoder block 11060.

The time deinterleaver block 11010 can perform a reverse process of theprocess performed by the time interleaver block 5060 illustrated in FIG.5. That is, the time deinterleaver block 11010 can deinterleave inputsymbols interleaved in the time domain into original positions thereof.

The cell deinterleaver block 11020 can perform a reverse process of theprocess performed by the cell interleaver block 5050 illustrated in FIG.5. That is, the cell deinterleaver block 11020 can deinterleavepositions of cells spread in one FEC block into original positionsthereof.

The constellation demapper block 11030 can perform a reverse process ofthe process performed by the constellation mapper block 5040 illustratedin FIG. 5. That is, the constellation demapper block 11030 can demap asymbol domain input signal to bit domain data. In addition, theconstellation demapper block 11030 may perform hard decision and outputdecided bit data. Furthermore, the constellation demapper block 11030may output a log-likelihood ratio (LLR) of each bit, which correspondsto a soft decision value or probability value. If the apparatus fortransmitting broadcast signals applies a rotated constellation in orderto obtain additional diversity gain, the constellation demapper block11030 can perform 2-dimensional LLR demapping corresponding to therotated constellation. Here, the constellation demapper block 11030 cancalculate the LLR such that a delay applied by the apparatus fortransmitting broadcast signals to the I or Q component can becompensated.

The cell-to-bit mux block 11040 can perform a reverse process of theprocess performed by the bit-to-cell demux block 5030 illustrated inFIG. 5. That is, the cell-to-bit mux block 11040 can restore bit datamapped by the bit-to-cell demux block 5030 to the original bit streams.

The bit deinterleaver block 11050 can perform a reverse process of theprocess performed by the bit interleaver 5020 illustrated in FIG. 5.That is, the bit deinterleaver block 11050 can deinterleave the bitstreams output from the cell-to-bit mux block 11040 in the originalorder.

The FEC decoder block 11060 can perform a reverse process of the processperformed by the FEC encoder block 5010 illustrated in FIG. 5. That is,the FEC decoder block 11060 can correct an error generated on atransmission channel by performing LDPC decoding and BCH decoding.

The second block 11100 processes an input data pipe according to MISOand can include the time deinterleaver block, cell deinterleaver block,constellation demapper block, cell-to-bit mux block, bit deinterleaverblock and FEC decoder block in the same manner as the first block 11000,as shown in FIG. 11. However, the second block 11100 is distinguishedfrom the first block 11000 in that the second block 11100 furtherincludes a MISO decoding block 11110. The second block 11100 performsthe same procedure including time deinterleaving operation to outputtingoperation as the first block 11000 and thus description of thecorresponding blocks is omitted.

The MISO decoding block 11110 can perform a reverse operation of theoperation of the MISO processing block 5110 illustrated in FIG. 5. Ifthe broadcast transmission/reception system according to an embodimentof the present invention uses STBC, the MISO decoding block 11110 canperform Alamouti decoding.

The third block 11200 processes an input data pipe according to MIMO andcan include the time deinterleaver block, cell deinterleaver block,constellation demapper block, cell-to-bit mux block, bit deinterleaverblock and FEC decoder block in the same manner as the second block11100, as shown in FIG. 11. However, the third block 11200 isdistinguished from the second block 11100 in that the third block 11200further includes a MIMO decoding block 11210. The basic roles of thetime deinterleaver block, cell deinterleaver block, constellationdemapper block, cell-to-bit mux block and bit deinterleaver blockincluded in the third block 11200 are identical to those of thecorresponding blocks included in the first and second blocks 11000 and11100 although functions thereof may be different from the first andsecond blocks 11000 and 11100.

The MIMO decoding block 11210 can receive output data of the celldeinterleaver for input signals of the m Rx antennas and perform MIMOdecoding as a reverse operation of the operation of the MIMO processingblock 5220 illustrated in FIG. 5. The MIMO decoding block 11210 canperform maximum likelihood decoding to obtain optimal decodingperformance or carry out sphere decoding with reduced complexity.Otherwise, the MIMO decoding block 11210 can achieve improved decodingperformance by performing MMSE detection or carrying out iterativedecoding with MMSE detection.

The fourth block 11300 processes the PLS-pre/PLS-post information andcan perform SISO or MISO decoding. The fourth block 11300 can carry outa reverse process of the process performed by the fourth block 5300described with reference to FIG. 5.

The basic roles of the time deinterleaver block, cell deinterleaverblock, constellation demapper block, cell-to-bit mux block and bitdeinterleaver block included in the fourth block 11300 are identical tothose of the corresponding blocks of the first, second and third blocks11000, 11100 and 11200 although functions thereof may be different fromthe first, second and third blocks 11000, 11100 and 11200.

The shortened/punctured FEC decoder 11310 included in the fourth block11300 can perform a reverse process of the process performed by theshortened/punctured FEC encoder block 5310 described with reference toFIG. 5. That is, the shortened/punctured FEC decoder 11310 can performde-shortening and de-puncturing on data shortened/punctured according toPLS data length and then carry out FEC decoding thereon. In this case,the FEC decoder used for data pipes can also be used for PLS.Accordingly, additional FEC decoder hardware for the PLS only is notneeded and thus system design is simplified and efficient coding isachieved.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

The demapping & decoding module according to an embodiment of thepresent invention can output data pipes and PLS information processedfor the respective paths to the output processor, as illustrated in FIG.11.

FIGS. 12 and 13 illustrate output processors according to embodiments ofthe present invention.

FIG. 12 illustrates an output processor according to an embodiment ofthe present invention. The output processor illustrated in FIG. 12corresponds to an embodiment of the output processor illustrated in FIG.8. The output processor illustrated in FIG. 12 receives a single datapipe output from the demapping & decoding module and outputs a singleoutput stream. The output processor can perform a reverse operation ofthe operation of the input formatting module illustrated in FIG. 2.

The output processor shown in FIG. 12 can include a BB scrambler block12000, a padding removal block 12100, a CRC-8 decoder block 12200 and aBB frame processor block 12300.

The BB scrambler block 12000 can descramble an input bit stream bygenerating the same PRBS as that used in the apparatus for transmittingbroadcast signals for the input bit stream and carrying out an XORoperation on the PRBS and the bit stream.

The padding removal block 12100 can remove padding bits inserted by theapparatus for transmitting broadcast signals as necessary.

The CRC-8 decoder block 12200 can check a block error by performing CRCdecoding on the bit stream received from the padding removal block12100.

The BB frame processor block 12300 can decode information transmittedthrough a BB frame header and restore MPEG-TSs, IP streams (v4 or v6) orgeneric streams using the decoded information.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

FIG. 13 illustrates an output processor according to another embodimentof the present invention. The output processor shown in FIG. 13corresponds to an embodiment of the output processor illustrated in FIG.8. The output processor shown in FIG. 13 receives multiple data pipesoutput from the demapping & decoding module. Decoding multiple datapipes can include a process of merging common data commonly applicableto a plurality of data pipes and data pipes related thereto and decodingthe same or a process of simultaneously decoding a plurality of servicesor service components (including a scalable video service) by theapparatus for receiving broadcast signals.

The output processor shown in FIG. 13 can include a BB descramblerblock, a padding removal block, a CRC-8 decoder block and a BB frameprocessor block as the output processor illustrated in FIG. 12. Thebasic roles of these blocks correspond to those of the blocks describedwith reference to FIG. 12 although operations thereof may differ fromthose of the blocks illustrated in FIG. 12.

A de-jitter buffer block 13000 included in the output processor shown inFIG. 13 can compensate for a delay, inserted by the apparatus fortransmitting broadcast signals for synchronization of multiple datapipes, according to a restored TTO (time to output) parameter.

A null packet insertion block 13100 can restore a null packet removedfrom a stream with reference to a restored DNP (deleted null packet) andoutput common data.

A TS clock regeneration block 13200 can restore time synchronization ofoutput packets based on ISCR (input stream time reference) information.

A TS recombining block 13300 can recombine the common data and datapipes related thereto, output from the null packet insertion block13100, to restore the original MPEG-TSs, IP streams (v4 or v6) orgeneric streams. The TTO, DNT and ISCR information can be obtainedthrough the BB frame header.

An in-band signaling decoding block 13400 can decode and output in-bandphysical layer signaling information transmitted through a padding bitfield in each FEC frame of a data pipe.

The output processor shown in FIG. 13 can BB-descramble the PLS-preinformation and PLS-post information respectively input through aPLS-pre path and a PLS-post path and decode the descrambled data torestore the original PLS data. The restored PLS data is delivered to asystem controller included in the apparatus for receiving broadcastsignals. The system controller can provide parameters necessary for thesynchronization & demodulation module, frame parsing module, demapping &decoding module and output processor module of the apparatus forreceiving broadcast signals.

The above-described blocks may be omitted or replaced by blocks havingsimilar r identical functions according to design.

FIG. 14 illustrates a coding & modulation module according to anotherembodiment of the present invention.

The coding & modulation module shown in FIG. 14 corresponds to anotherembodiment of the coding & modulation module illustrated in FIGS. 1 to5.

To control QoS for each service or service component transmitted througheach data pipe, as described above with reference to FIG. 5, the coding& modulation module shown in FIG. 14 can include a first block 14000 forSISO, a second block 14100 for MISO, a third block 14200 for MIMO and afourth block 14300 for processing the PLS-pre/PLS-post information. Inaddition, the coding & modulation module can include blocks forprocessing data pipes equally or differently according to the design.The first to fourth blocks 14000 to 14300 shown in FIG. 14 are similarto the first to fourth blocks 5000 to 5300 illustrated in FIG. 5.

However, the first to fourth blocks 14000 to 14300 shown in FIG. 14 aredistinguished from the first to fourth blocks 5000 to 5300 illustratedin FIG. 5 in that a constellation mapper 14010 included in the first tofourth blocks 14000 to 14300 has a function different from the first tofourth blocks 5000 to 5300 illustrated in FIG. 5, a rotation & I/Qinterleaver block 14020 is present between the cell interleaver and thetime interleaver of the first to fourth blocks 14000 to 14300illustrated in FIG. 14 and the third block 14200 for MIMO has aconfiguration different from the third block 5200 for MIMO illustratedin FIG. 5. The following description focuses on these differencesbetween the first to fourth blocks 14000 to 14300 shown in FIG. 14 andthe first to fourth blocks 5000 to 5300 illustrated in FIG. 5.

The constellation mapper block 14010 shown in FIG. 14 can map an inputbit word to a complex symbol. However, the constellation mapper block14010 may not perform constellation rotation, differently from theconstellation mapper block shown in FIG. 5. The constellation mapperblock 14010 shown in FIG. 14 is commonly applicable to the first, secondand third blocks 14000, 14100 and 14200, as described above.

The rotation & I/Q interleaver block 14020 can independently interleavein-phase and quadrature-phase components of each complex symbol ofcell-interleaved data output from the cell interleaver and output thein-phase and quadrature-phase components on a symbol-by-symbol basis.The number of number of input data pieces and output data pieces of therotation & I/Q interleaver block 14020 is two or more which can bechanged by the designer. In addition, the rotation & I/Q interleaverblock 14020 may not interleave the in-phase component.

The rotation & I/Q interleaver block 14020 is commonly applicable to thefirst to fourth blocks 14000 to 14300, as described above. In this case,whether or not the rotation & I/Q interleaver block 14020 is applied tothe fourth block 14300 for processing the PLS-pre/post information canbe signaled through the above-described preamble.

The third block 14200 for MIMO can include a Q-block interleaver block14210 and a complex symbol generator block 14220, as illustrated in FIG.14.

The Q-block interleaver block 14210 can permute a parity part of anFEC-encoded FEC block received from the FEC encoder. Accordingly, aparity part of an LDPC H matrix can be made into a cyclic structure likean information part. The Q-block interleaver block 14210 can permute theorder of output bit blocks having Q size of the LDPC H matrix and thenperform row-column block interleaving to generate final bit streams.

The complex symbol generator block 14220 receives the bit streams outputfrom the Q-block interleaver block 14210, maps the bit streams tocomplex symbols and outputs the complex symbols. In this case, thecomplex symbol generator block 14220 can output the complex symbolsthrough at least two paths. This can be modified by the designer.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

The coding & modulation module according to another embodiment of thepresent invention, illustrated in FIG. 14, can output data pipes,PLS-pre information and PLS-post information processed for respectivepaths to the frame structure module.

FIG. 15 illustrates a demapping & decoding module according to anotherembodiment of the present invention.

The demapping & decoding module shown in FIG. 15 corresponds to anotherembodiment of the demapping & decoding module illustrated in FIG. 11.The demapping & decoding module shown in FIG. 15 can perform a reverseoperation of the operation of the coding & modulation module illustratedin FIG. 14.

As shown in FIG. 15, the demapping & decoding module according toanother embodiment of the present invention can include a first block15000 for SISO, a second block 11100 for MISO, a third block 15200 forMIMO and a fourth block 14300 for processing the PLS-pre/PLS-postinformation. In addition, the demapping & decoding module can includeblocks for processing data pipes equally or differently according todesign. The first to fourth blocks 15000 to 15300 shown in FIG. 15 aresimilar to the first to fourth blocks 11000 to 11300 illustrated in FIG.11.

However, the first to fourth blocks 15000 to 15300 shown in FIG. 15 aredistinguished from the first to fourth blocks 11000 to 11300 illustratedin FIG. 11 in that an I/Q deinterleaver and derotation block 15010 ispresent between the time interleaver and the cell deinterleaver of thefirst to fourth blocks 15000 to 15300, a constellation mapper 15010included in the first to fourth blocks 15000 to 15300 has a functiondifferent from the first to fourth blocks 11000 to 11300 illustrated inFIG. 11 and the third block 15200 for MIMO has a configuration differentfrom the third block 11200 for MIMO illustrated in FIG. 11. Thefollowing description focuses on these differences between the first tofourth blocks 15000 to 15300 shown in FIG. 15 and the first to fourthblocks 11000 to 11300 illustrated in FIG. 11.

The I/Q deinterleaver & derotation block 15010 can perform a reverseprocess of the process performed by the rotation & I/Q interleaver block14020 illustrated in FIG. 14. That is, the I/Q deinterleaver &derotation block 15010 can deinterleave I and Q componentsI/Q-interleaved and transmitted by the apparatus for transmittingbroadcast signals and derotate complex symbols having the restored I andQ components.

The I/Q deinterleaver & derotation block 15010 is commonly applicable tothe first to fourth blocks 15000 to 15300, as described above. In thiscase, whether or not the I/Q deinterleaver & derotation block 15010 isapplied to the fourth block 15300 for processing the PLS-pre/postinformation can be signaled through the above-described preamble.

The constellation demapper block 15020 can perform a reverse process ofthe process performed by the constellation mapper block 14010illustrated in FIG. 14. That is, the constellation demapper block 15020can demap cell-deinterleaved data without performing derotation.

The third block 15200 for MIMO can include a complex symbol parsingblock 15210 and a Q-block deinterleaver block 15220, as shown in FIG.15.

The complex symbol parsing block 15210 can perform a reverse process ofthe process performed by the complex symbol generator block 14220illustrated in FIG. 14. That is, the complex symbol parsing block 15210can parse complex data symbols and demap the same to bit data. In thiscase, the complex symbol parsing block 15210 can receive complex datasymbols through at least two paths.

The Q-block deinterleaver block 15220 can perform a reverse process ofthe process carried out by the Q-block interleaver block 14210illustrated in FIG. 14. That is, the Q-block deinterleaver block 15220can restore Q size blocks according to row-column deinterleaving,restore the order of permuted blocks to the original order and thenrestore positions of parity bits to original positions according toparity deinterleaving.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

As illustrated in FIG. 15, the demapping & decoding module according toanother embodiment of the present invention can output data pipes andPLS information processed for respective paths to the output processor.

As described above, the apparatus and method for transmitting broadcastsignals according to an embodiment of the present invention canmultiplex signals of different broadcast transmission/reception systemswithin the same RF channel and transmit the multiplexed signals and theapparatus and method for receiving broadcast signals according to anembodiment of the present invention can process the signals in responseto the broadcast signal transmission operation. Accordingly, it ispossible to provide a flexible broadcast transmission and receptionsystem.

FIG. 16 illustrates a waveform generation module and a synchronization &demodulation module according to another embodiment of the presentinvention.

FIG. 16(a) shows the waveform generation module according to anotherembodiment of the present invention. The waveform generation module maycorrespond to the aforementioned waveform generation module. The waveform generation module according to another embodiment may include a newreference signal insertion & PAPR reduction block. The new referencesignal insertion & PAPR reduction block may correspond to theaforementioned reference signal insertion & PAPR reduction block.

The present invention provides a method for generating a continuouspilot (CP) pattern inserted into predetermined positions of each signalblock. In addition, the present invention provides a method foroperating CPs using a small-capacity memory (ROM). The new referencesignal insertion & PAPR reduction block according to the presentinvention may operate according to the methods for generating andoperating a CP pattern provided by the present invention.

FIG. 16(b) illustrates a synchronization & demodulation module accordingto another embodiment of the present invention. The synchronization &demodulation module may correspond to the aforementioned synchronization& demodulation module. The synchronization & demodulation module mayinclude a new reference signal detector. The new reference signaldetector may correspond to the aforementioned reference signal detector.

The new reference signal detector according to the present invention mayperform operation of a receiver using CPs according to the method forgenerating and operating CPs, provided by the present invention. CPs maybe used for synchronization of the receiver. The new reference signaldetector may detect a received reference signal to aid insynchronization or channel estimation of the receiver. Here,synchronization may be performed through coarse auto frequency control(AFC), fine AFC and/or common phase error correction (CPE).

At a transmitter, various cells of OFDM symbols may be modulated throughreference information. The reference information may be called a pilot.Pilots may include a SP (scattered pilot), CP (continual pilot), edgepilot, FSS (frame signaling symbol) pilot, FES (frame edge symbol)pilot, etc. Each pilot may be transmitted at a specific boosted powerlevel according to pilot type or pattern.

The CP may be one of the aforementioned pilots. A small quantity of CPsmay be randomly distributed in OFDM symbols and operated. In this case,an index table in which CP position information is stored in a memorymay be efficient. The index table may be referred to as a referenceindex table, a CP set, a CP group, etc. The CP set may be determineddepending on FFT size and SP pattern.

CPs may be inserted into each frame. Specifically, CPs can be insertedinto symbols of each frame. The CPs may be inserted in a CP patternaccording to the index table. However, the size of the index table mayincrease as the SP pattern is diversified and the number of activecarriers (NOC) increases.

To solve this problem, the present invention provides a method foroperating CPs using a small-capacity memory. The present inventionprovides a pattern reversal method and a position multiplexing method.According to these methods, storage capacity necessary for the receivercan be decreased.

The design concept of a CP pattern may be as follows. The number ofactive data carriers (NOA) in each OFDM symbol is held constant. Theconstant NOA may conform to a predetermined NOC (or FFT mode) and SPpattern.

The CP pattern can be changed based on NOC and SP pattern to check thefollowing two conditions: reduction of signaling information; andsimplification of interaction between a time interleaver and carriermapping.

Subsequently, CPs to be positioned in an SP-bearing carrier and anon-SP-bearing carrier can be fairly selected. This selection processmay be carried out for a frequency selective channel. The selectionprocess may be performed such that the CPs are randomly distributed withroughly even distribution over a spectrum. The number of CP positionsmay increase as the NOC increases. This may serve to preserve overheadof the CPs.

The pattern reversal method will now be briefly described. A CP patternthat can be used in an NOC or SP pattern may be generated based on theindex table. CP position values may be arranged into an index tablebased on the smallest NOC. The index table may be referred to as areference index table. Here, the CP position values may be randomlylocated. For a larger NOC, the index table can be extended by reversingthe distribution pattern of the index table. Extension may not beachieved by simple repetition according to a conventional technique.Cyclic shifting may precede reversal of the distribution pattern of theindex table according to an embodiment. According to the patternreversal method, CPs can be operated even with a small-capacity memory.The pattern reversal method may be applied to NOC and SP modes. Inaddition, according to the pattern reversal method, CP positions may beevenly and randomly distributed over the spectrum. The pattern reversalmethod will be described in more detail later.

The position multiplexing method will now be briefly described. Like thepattern reversal method, a CP pattern that can be used in the NOC or SPpattern may be generated based on the index table. First, positionvalues for randomly positioning CPs may be aligned into an index table.This index table may be referred to as a reference index table. Theindex table may be designed in a sufficiently large size to be usedfor/applied to all NOC modes. Then, the index table may be multiplexedthrough various methods such that CP positions are evenly and randomlydistributed over the spectrum for an arbitrary NOC. The positionmultiplexing method will be described in more detail later.

FIG. 17 illustrates definition of a CP bearing SP and a CP not bearingSP according to an embodiment of the present invention.

A description will be given of a random CP position generator prior todescription of the pattern reversal method and the position multiplexingmethod. The pattern reversal method and the position multiplexing methodmay require the random CP position generator.

Several assumptions may be necessary for the random CP positiongenerator. First, it can be assumed that CP positions are randomlyselected by a PN generator at a predetermined NOC. That is, it can beassumed that the CP positions are randomly generated using a PRBSgenerator and provided to the reference index table. It can be assumedthat the NOA in each OFDM symbol is constantly maintained. The NOA ineach OFDM symbol may be constantly maintained by appropriately selectingCP bearing SPs and CP not bearing SPs.

In FIG. 17, uncolored portions represent CP not bearing SPs and coloredportions represent CP bearing SPs.

FIG. 18 shows a reference index table according to an embodiment of thepresent invention.

The reference index table shown in FIG. 18 may be a reference indextable generated using the aforementioned assumptions. The referenceindex table considers 8K FFT mode (NOC: 6817) and SP mode (Dx:2, Dy:4).The index table shown in FIG. 18(a) may be represented as a graph shownin FIG. 18(b).

FIG. 19 illustrates the concept of configuring a reference index tablein CP pattern generation method #1 using the position multiplexingmethod.

A description will be given of CP pattern generation method #1 using theposition multiplexing method.

When a reference index table is generated, the index table can bedivided into sub index tables having a predetermined size. Different PNgenerators (or different seeds) may be used for the sub index tables togenerate CP positions. FIG. 19 shows a reference index table considering8, 16 and 32K FFT modes. That is, in the case of 8K FFT mode, a singlesub index table can be generated by PN1. In the case of 16K FFT mode,two sub index tables can be respectively generated by PN1 and PN2. TheCP positions may be generated based on the aforementioned assumptions.

For example, when the 16K FFT mode is supported, CP position valuesobtained through a PN1 and PN2 generator can be sequentially arranged todistribute all CP positions. When the 32K FFT mode is supported, CPposition values obtained through a PN3 and PN4 generator can beadditionally arranged to distribute all CP positions.

Accordingly, CPs can be evenly and randomly distributed over thespectrum. In addition, a correlation property between CP positions canbe provided.

FIG. 20 illustrates a method for generating a reference index table inCP pattern generation method #1 using the position multiplexing methodaccording to an embodiment of the present invention.

In the present embodiment, CP position information may be generated inconsideration of an SP pattern with Dx=3 and Dy=4. In addition, thepresent embodiment may be implemented in 8K/16K/32K FFT modes (NOC:1817/13633/27265).

CP position values may be stored in a sub index table using the 8K FFTmode as a basic mode. When 16K or higher FFT modes are supported, subindex tables may be added to the stored basic sub index table. Values ofthe added sub index tables may be obtained by adding a predeterminedvalue to the stored basic sub index table or shifting the basic subindex table.

CP position values provided to the ends of sub index tables PN1, PN2 andPN3 may refer to values necessary when the corresponding sub indextables are extended. That is, the CP position values may be values formultiplexing. The CP position values provided to the ends of the subindex tables are indicated by ovals in FIG. 20.

The CP position values v provided to the ends of the sub index tablesmay be represented as follows.

v=i·D _(x) ·D _(y)  [Expression 1]

Here, v can be represented as an integer multiple i of D_(x)·D_(y). Whenthe 8K FFT mode is applied, the last position value of sub index tablePN1 may not be applied. When the 16K FFT mode is applied, the lastposition value of sub index table PN1 is applied whereas the lastposition value of sub index table PN2 may not be applied. Similarly,when the 32K FFT mode is applied, all the last position values of subindex tables PN1, PN2 and PN3 may be applied.

In CP pattern generation method #1 using the position multiplexingmethod, the aforementioned multiplexing rule can be represented by thefollowing Expression. The following Expression may be an equation forgenerating CP positions to be used in each FFT mode from a predeterminedreference index table.

$\begin{matrix}{\mspace{79mu} {{{{{{CP\_}8{K(k)}} = {{PN}\; 1(k)}},{{{for}\mspace{14mu} 1} \leq k \leq {S_{{PN}_{1}} - 1}}}{CP\_}16{K(k)}} = \left\{ {{\begin{matrix}{{{{PN}\; 1(k)},{{{if}\mspace{14mu} 1} \leq k \leq S_{{PN}\; 1}}}\mspace{14mu}} \\{{{\alpha_{1} + {{PN}\; 2\left( {k - S_{{PN}\; 1}} \right)}},\; {{{{elseif}\mspace{14mu} S_{{PN}\; 1}} + 1} \leq k \leq {S_{{PN}\; 12} - 1}}}\;}\end{matrix}{CP\_}32{K(k)}} = \left\{ \begin{matrix}{{{{PN}\; 1(k)},{{{if}\mspace{14mu} 1} \leq k \leq S_{{PN}\; 1}}}\;} \\{{\alpha_{1} + {{PN}\; 2\left( {k - S_{{PN}\; 1}} \right)}},\; {{{{elseif}\mspace{14mu} S_{{PN}\; 1}} + 1} \leq k \leq S_{{PN}\; 12}}} \\{{\alpha_{2} + {{PN}\; 3\left( {k - S_{{PN}\; 12}} \right)}},\; {{{{elseif}\mspace{14mu} S_{{PN}\; 12}} + 1} \leq k \leq S_{{PN}\; 123}}} \\{{\alpha_{3} + {{PN}\; 4\left( {k - S_{{PN}\; 123}} \right)}},\; {{{{elseif}\mspace{14mu} S_{{PN}\; 123}} + 1} \leq k \leq S_{{PN}\; 1234}}}\end{matrix} \right.} \right.}} & \left\lbrack {{Expression}\mspace{14mu} 2} \right\rbrack\end{matrix}$

-   -   where        -   S_(PN12)=S_(PN1)+S_(PN2)        -   S_(PN123)=S_(PN1)+S_(PN2)+S_(PN3)        -   S_(PN1234)=S_(PN1)+S_(PN2)+S_(PN3)+S_(PN4)

Expression 2 may be an equation for generating CP position values to beused in each FFT mode based on the predetermined reference index table.Here, CP_8/16/32K respectively denote CP patterns in 8K, 16K and 32K FFTmodes and PN_1/2/3/4 denote sub index table names. S_(PN) _(_)_(1/2/3/4) respectively represent the sizes of sub index tables PN1,PN2, PN3 and PN4 and α_(1/2/3) represent shifting values for evenlydistributing added CP positions.

In CP_8K(k) and CP_16K(k), k is limited to S_(PN1)−1 and S_(PN12)−1.Here, −1 is added since the last CP position value v is excluded, asdescribed above.

FIG. 21 illustrates the concept of configuring a reference index tablein CP pattern generation method #2 using the position multiplexingmethod according to an embodiment of the present invention.

CP pattern generation method #2 using the position multiplexing methodwill now be described.

CP pattern generation method #2 using the position multiplexing methodmay be performed in a manner that a CP pattern according to FFT mode issupported. CP pattern generation method #2 may be performed in such amanner that PN1, PN2, PN3 and PN4 are multiplexed to support a CP suitedto each FFT mode. Here, PN1, PN2, PN3 and PN4 are sub index tables andmay be composed of CP positions generated by different PN generators.PN1, PN2, PN3 and PN4 may be assumed to be sequences in which CPposition values are distributed randomly and evenly. While the referenceindex table may be generated through a method similar to theaforementioned CP pattern generation method #1 using the positionmultiplexing method, a detailed multiplexing method may differ from CPpattern generation method #1.

A pilot density block can be represented as N_(blk). The number ofallocated pilot density blocks N_(blk) may depend on FFT mode in thesame bandwidth. That is, one pilot density block N_(blk) may beallocated in the case of 8K FFT mode, two pilot density blocks N_(blk)may be allocated in the case of 16K FFT mode and four pilot densityblocks N_(blk) may be allocated in the case of 32K FFT mode. PN1 to PN4may be multiplexed in an allocated region according to FFT mode togenerate CP patterns.

PN1 to PN4 may be generated such that a random and even CP distributionis obtained. Accordingly, the influence of an arbitrary specific channelmay be mitigated. Particularly, PN1 can be designed such thatcorresponding CP position values are disposed in the same positions inphysical spectrums of 8K, 16K and 32K. In this case, a receptionalgorithm for synchronization can be implemented using simple PN1.

In addition, PN1 to PN4 may be designed such that they have excellentcross correlation characteristics and auto correlation characteristics.

In the case of PN2 in which CP positions are additionally determined inthe 16K FFT mode, the CP positions can be determined such that PN2 hasexcellent auto correlation characteristics and even distributioncharacteristics with respect to the position of PN1 determined in the 8KFFT mode. Similarly, in the case of PN3 and PN4 in which CP positionsare additionally determined in the 32K FFT mode, the CP positions can bedetermined such that auto correlation characteristics and evendistribution characteristics are optimized based on the positions of PN1and PN2 determined in 16K FFT mode.

CPs may not be disposed in predetermined portions of both edges of thespectrum. Accordingly, it is possible to mitigate loss of some CPs whenan integral frequency offset (ICFO) is generated.

FIG. 22 illustrates a method for generating a reference index table inCP pattern generation method #2 using the position multiplexing method.

PN1 can be generated in case of the 8K FFT mode, PN1 and PN2 can begenerated in case of the 16K FFT mode and PN1, PN2, PN3 and PN4 can begenerated in case of the 32K FFT mode. The generation process may beperformed according to a predetermined multiplexing rule.

FIG. 22 illustrates that two pilot density blocks N_(blk) in case of the16K FFT mode and four pilot density blocks N_(blk) in case of the 32KFFT mode can be included in a region which can be represented by asingle pilot density block N_(blk) on the basis of the 8K FFT mode. PNsgenerated according to each FFT mode can be multiplexed to generate a CPpattern.

In the case of 8K FFT mode, a CP pattern can be generated using PN1.That is, PN1 may be a CP pattern in the 8K FFT mode.

In the case of 16K FFT mode, PN1 can be positioned in the first pilotdensity block (first N_(blk)) and PN2 can be disposed in the secondpilot density block (second N_(blk)) to generate a CP pattern.

In the case of 32K FFT mode, PN1 can be disposed in the first pilotdensity block (first N_(blk)), PN2 can be disposed in the second pilotdensity block (second N_(blk)), PN3 can be disposed in the third pilotdensity block (third N_(blk)) and PN4 can be disposed in the fourthpilot density block (fourth N_(blk)) to generate a CP pattern. WhilePN1, PN2, PN3 and PN4 are sequentially disposed in the presentembodiment, PN2 may be disposed in the third pilot density block (thirdN_(blk)) in order to insert CPs into similar positions of the spectrumas in the 16K FFT mode.

In CP pattern generation method #2 using the position multiplexingmethod, the aforementioned multiplexing rule can be represented by thefollowing Expression. The following Expression may be an equation forgenerating CP positions to be used in each FFT mode from a predeterminedreference index table.

$\begin{matrix}{\mspace{79mu} {{{{CP\_}8{K(k)}} = {{PN}\; 1(k)}},{{{CP\_}16{K(k)}} = \left\{ \begin{matrix}{{{PN}\; 1\begin{pmatrix}{{{{ceil}\left( \frac{k}{2N_{blk}} \right)} \cdot N_{blk}} +} \\{{mod}\left( {k,{2N_{blk}}} \right)}\end{pmatrix}},} & \begin{matrix}\begin{matrix}{0 \leq {{mod}\; \left( {k,{2N_{blk}}} \right)} <} \\N_{blk}\end{matrix} \\\;\end{matrix} \\{{{PN}\; 2\begin{pmatrix}{{{{c{eil}}\left( \frac{k}{2N_{blk}} \right)} \cdot N_{blk}} +} \\{{mod}\left( {\left( {k - N_{blk}} \right),{2N_{blk}}} \right)}\end{pmatrix}},} & \begin{matrix}{N_{blk} \leq {{mod}\; \left( {k,{2N_{blk}}} \right)} <} \\{2N_{blk}}\end{matrix}\end{matrix} \right.}}} & \left\lbrack {{Expression}\mspace{14mu} 3} \right\rbrack \\{{{CP\_}32{K(k)}} = \left\{ \begin{matrix}{{{PN}\; 1\begin{pmatrix}{{{{c{eil}}\left( \frac{k}{4N_{blk}} \right)} \cdot N_{blk}} +} \\{{mod}\left( {k,{4N_{blk}}} \right)}\end{pmatrix}},} & \begin{matrix}{0 \leq {{mod}\; \left( {k,{4N_{blk}}} \right)} <} \\N_{blk}\end{matrix} \\{{{PN}\; 2\begin{pmatrix}{{{{c{eil}}\left( \frac{k}{4N_{blk}} \right)} \cdot N_{blk}} +} \\{{mod}\left( {\left( {k - N_{blk}} \right),{4N_{blk}}} \right)}\end{pmatrix}},} & \begin{matrix}{N_{blk} \leq {{mod}\; \left( {k,{4N_{blk}}} \right)} <} \\{2N_{blk}}\end{matrix} \\{{{PN}\; 3\begin{pmatrix}{{{{c{eil}}\left( \frac{k}{4N_{blk}} \right)} \cdot N_{blk}} +} \\{{mod}\left( {\left( {k - {2N_{blk}}} \right),{4N_{blk}}} \right)}\end{pmatrix}},} & \begin{matrix}{{2N_{blk}} \leq {{mod}\; \left( {k,{4N_{blk}}} \right)} <} \\{3N_{blk}}\end{matrix} \\{{{PN}\; 4\begin{pmatrix}{{{{c{eil}}\left( \frac{k}{4N_{blk}} \right)} \cdot N_{blk}} +} \\{{mod}\left( {\left( {k - {3N_{blk}}} \right),{4N_{blk}}} \right)}\end{pmatrix}},} & \begin{matrix}{{3N_{blk}} \leq {{mod}\; \left( {k,{4N_{blk}}} \right)} <} \\{4N_{blk}}\end{matrix}\end{matrix} \right.} & \;\end{matrix}$

Expression 3 may be an equation for generating CP position values to beused in each FFT mode based on the predetermined reference index table.Here, CP_8/16/32K respectively denote CP patterns in 8K, 16K and 32K FFTmodes and PN1 to PN4 denote sequences. These sequences may be fourpseudo random sequences. In addition, ceil(X), ceiling function of X,represents a function outputting a minimum value from among integersequal to or greater than X and mod(X,N) is a modulo function capable ofoutputting a remainder obtained when X is divided by N.

For the 16K FFT mode and the 32K FFT mode, sequences PN1 to PN4 may bemultiplexed in offset positions determined according to each FFT mode.In the above Expression, offset values may be represented by modulooperation values of predetermined integer multiples of basic N_(blk).The offset values may be different values.

FIG. 23 illustrates a method for generating a reference index table inCP pattern generation method #3 using the position multiplexing methodaccording to an embodiment of the present invention.

In the present embodiment, PN1 to PN4 may be assumed to be sequences inwhich CP position values are distributed randomly and evenly. Inaddition, PN1 to PN4 may be optimized to satisfy correlation and evendistribution characteristics for 8K, 16K and 32K, as described above.

The present embodiment may relate to a scattered pilot pattern forchannel estimation. In addition, the present embodiment may relate to acase in which distance Dx in the frequency direction is 8 and distanceDy in the time direction is 2. The present embodiment may be applicableto other patterns.

As described above, PN1 can be generated in the case of 8K FFT mode, PN1and PN2 can be generated in the case of 16K FFT mode and PN1, PN2, PN3and PN4 can be generated in the case of 32K FFT mode. The generationprocess may be performed according to a predetermined multiplexing rule.

FIG. 23 shows that two pilot density blocks N_(blk) in case of the 16KFFT mode and four pilot density blocks N_(blk) in case of the 32K FFTmode can be included in a region which can be represented by a singlepilot density block N_(blk) on the basis of the 8K FFT mode.

PNs generated according to each FFT mode can be multiplexed to generatea CP pattern. In each FFT mode, CPs may be disposed overlapping with SPs(SP bearing) or disposed not overlapping with SPs (non-SP bearing). Inthe present embodiment, a multiplexing rule for SP bearing or non-SPbearing CP positioning can be applied in order to dispose pilots in thesame positions in the frequency domain.

In the case of SP bearing, PN1 to PN4 may be disposed such that CPpositions are distributed randomly and evenly for an SP offset pattern.Here, PN1 to PN4 may be sequences forming an SP bearing set. PN1 to PN4may be positioned according to the multiplexing rule for each FFT mode.That is, in the case of 16K FFT mode, PN2 added to PN1 can be disposedin positions other than an SP offset pattern in which PN1 is positioned.A position offset with respect to PN2 may be set such that PN2 ispositioned in positions other than the SP offset pattern in which PN1 ispositioned or PN2 may be disposed in a pattern determined through arelational expression. Similarly, in the case of 32K FFT mode, PN3 andPN4 may be configured to be disposed in positions other than SP offsetpatterns in which PN1 and PN2 are positioned.

In case of non-SP bearing, PN1 to PN4 may be positioned according to arelational expression. Here, PN1 to PN4 may be sequences forming anon-SP bearing set.

In CP pattern generation method #3 using the position multiplexingmethod, the aforementioned multiplexing rule can be represented by thefollowing Expression s. The following Expression s may be equations forgenerating CP positions to be used in each FFT mode from a predeterminedreference index table.

$\begin{matrix}{{\left. \mspace{85mu} 1 \right){\mspace{11mu} \;}{SP}\mspace{14mu} {bearing}\mspace{14mu} {set}\text{:}\mspace{14mu} {PN}\; 1_{sp}(k)},\mspace{85mu} {{PN}\; 2_{sp}(k)},{{PN}\; 3_{sp}(k)},{{PN}\; 4_{sp}(k)},\mspace{79mu} {{{CP}_{sp}\_ 8{K(k)}} = {{PN}\; 1_{sp}(k)}},\mspace{79mu} {{{CP}_{sp}\_ 16{K(k)}} = \left\{ {{\begin{matrix}{{{PN}\; 1_{sp}{(k)2}},} \\{{{{PN}\; 2_{sp}{(k)2}} + \alpha_{16K}},}\end{matrix}{CP}_{sp}\_ 32{K(k)}} = \left\{ \begin{matrix}{{{CP\_}16{K(k)}^{*}2} = \left\{ \begin{matrix}{\left( {{PN}\; 1_{sp}{(k)2}} \right)2} \\{\left( {{{PN}\; 1_{sp}{(k)2}} + \alpha_{16K}} \right)2}\end{matrix} \right.} \\{{{PN}\; 3_{sp}(k)^{*}4} + {\alpha 1}_{32K}} \\{{{PN}\; 4_{sp}(k)^{*}4} + {\alpha 2}_{32K}}\end{matrix} \right.} \right.}} & \left\lbrack {{Expression}\mspace{14mu} 4} \right\rbrack \\{{{\left. \mspace{79mu} 2 \right)\mspace{14mu} {Non}\mspace{14mu} {SP}\mspace{14mu} {bearing}\mspace{14mu} {set}\text{:}\mspace{14mu} {PN}\; 1_{nonsp}(k)},\mspace{79mu} {{PN}\; 2_{nonsp}(k)},{{PN}\; 3_{nonsp}(k)},{{PN}\; 4_{nonsp}(k)}}\mspace{79mu} {{{{CP}_{nonsp}\_ 8{K(k)}} = {{PN}\; 1_{nonsp}(k)}},\mspace{79mu} {{{CP}_{nonsp}\_ 16{K(k)}} = \left\{ {{\begin{matrix}{{{PN}\; 1_{nonsp}{(k)2}},} \\{{{{PN}\; 2_{nonsp}{(k)2}} + \beta_{16K}},}\end{matrix}{CP}_{nonsp}\_ 32{K(k)}} = \left\{ \begin{matrix}{{{CP}_{nonsp}\_ 16{K(k)}^{*}2} = \left\{ \begin{matrix}{\left( {{PN}\; 1_{nonsp}{(k)2}} \right)2} \\{\left( {{{PN}\; 1_{nonsp}{(k)2}} + \beta_{16K}} \right)2}\end{matrix} \right.} \\{{{PN}\; 3_{nonsp}(k)^{*}4} + {\beta 1}_{32K}} \\{{{PN}\; 4_{nonsp}(k)^{*}4} + {\beta 2}_{32K}}\end{matrix} \right.} \right.}}} & \left\lbrack {{Expression}\mspace{14mu} 5} \right\rbrack \\{\mspace{79mu} {{{{CP\_}8{K(k)}} = \left\{ {{{CP}_{sp}\_ 8{K(k)}},{{CP}_{nonsp}\_ 8{K(k)}}} \right\}}\mspace{79mu} {{{CP\_}16{K(k)}} = \left\{ {{{CP}_{sp}\_ 16{K(k)}},{{CP}_{nonsp}\_ 16{K(k)}}} \right\}}\mspace{79mu} {{{CP\_}32{K(k)}} = \left\{ {{{CP}_{sp}\_ 32{K(k)}},{{CP}_{nonsp}\_ 32{K(k)}}} \right\}}}} & \left\lbrack {{Expression}\mspace{14mu} 6} \right\rbrack\end{matrix}$

The above Expression s may be equations for generating CP positionvalues to be used in each FFT mode based on the predetermined referenceindex table. Here, CP_8/16/32K respectively denote CP patterns in 8K,16K and 32K FFT modes and CP_(sp) _(—) 8/16/32K respectively denote SPbearing CP patterns in 8K, 16K and 32K FFT modes. CP_(nonsp) _(—)8/16/32K respectively represent non-SP bearing CP patterns in 8K, 16Kand 32K FFT modes and PN1_(sp), PN2_(sp), PN3_(sp) and PN4_(sp)represent sequences for SP bearing pilots. These sequences may be fourpseudo random sequences. These sequences may be included in an SP beingset. PN1_(nonsp), PN2_(nonsp), PN3_(nonsp) and PN4_(nonsp) denotesequences for non-SP bearing pilots. These sequences may be four pseudorandom sequences and may be included in a non-SP bearing set. Inaddition, α_(16K), α1_(32K), α2_(32K), β_(16K), β1_(32K) and β2_(32K)represent CP position offsets.

Respective SP bearing CP patterns can be generated using PN1_(sp),PN2_(sp), PN3_(sp) and PN4_(sp), as represented by Expression 4.Respective non-SP bearing patterns can be generated using PN1_(nonsp),PN2_(nonsp), PN3_(nonsp) and PN4_(nonsp), as represented by Expression5. As represented by Expression 6, the CP pattern of each FFT mode canbe composed of an SP bearing CP pattern and a non-SP bearing CP pattern.That is, an SP bearing CP index table can be added to a non-SP bearingCP index table to generate a reference index table. Consequently, CPinsertion can be performed according to the non-SP bearing CP indextable and the SP bearing CP index table. Here, non-SP bearing CPposition values may be called a common CP set and SP bearing CP positionvalues may be called an additional CP set.

CP position offsets may be values predetermined for multiplexing, asdescribed above. The CP position offsets may be allocated to the samefrequency irrespective of FFT mode or used to correct CPcharacteristics.

FIG. 24 illustrates the concept of configuring a reference index tablein CP pattern generation method #1 using the pattern reversal method.

CP pattern generation method #1 using the pattern reversal method willnow be described.

As described above, when the reference index table is generated, thetable can be divided into sub index tables having a predetermined size.The sub index tables may include CP positions generated using differentPN generators (or different seeds).

In the pattern reversal method, two sub index tables necessary in the8K, 16K and 32K FFT modes can be generated by two different PNgenerators. Two sub index tables additionally necessary in the 32K FFTmode can be generated by reversing the pre-generated two sub indextables.

That is, when the 16K FFT mode is supported, CP positions according toPN1 and PN2 can be sequentially arranged to obtain a CP positiondistribution. When the 32K FFT mode is supported, however, CP positionsaccording to PN1 and PN2 can be reversed to obtain a CP positiondistribution.

Accordingly, a CP index table in the 32K FFT mode can include a CP indextable in the 16K FFT mode. In addition, the CP index table in the 16KFFT mode can include a CP index table in the 8K FFT mode. According toan embodiment, the CP index table in the 32K FFT mode may be stored andthe CP index tables in the 8K and 16K FFT modes may beselected/extracted from the CP index table in the 32K FFT mode togenerate the CP index tables in the 8K and 16K FFT modes.

According to the aforementioned pattern reversal method, CP positionscan be distributed evenly and randomly over the spectrum. In addition,the size of a necessary reference index table can be reduced compared tothe aforementioned position multiplexing method. Furthermore, memorystorage capacity necessary for the receiver can be decreased.

FIG. 25 illustrates a method for generating a reference index table inCP pattern generation method #1 using the pattern reversal methodaccording to an embodiment of the present invention.

In the present embodiment, CP position information may be generated inconsideration of an SP pattern with Dx=3 and Dy=4. In addition, thepresent embodiment may be implemented in 8K/16K/32K FFT modes (NOC:1817/13633/27265).

CP position values may be stored in a sub index table using the 8K FFTmode as a basic mode. When 16K or higher FFT modes are supported, subindex tables may be added to the stored basic sub index table. Values ofthe added sub index tables may be obtained by adding a predeterminedvalue to the stored basic sub index table or shifting the basic subindex table.

The 32K FFT mode index table can be generated using sub index tablesobtained by reversing sub index tables of PN1 and PN2.

CP position values provided to the ends of sub index tables PN1 and PN2may refer to values necessary when the corresponding sub index tablesare extended. That is, the CP position values may be values formultiplexing. The CP position values provided to the ends of the subindex tables are indicated by ovals in FIG. 20.

The CP position values v provided to the ends of the sub index tablesmay be represented as follows.

v=i·D _(x) ·D _(y)  [Expression 7]

Here, v can be represented as an integer multiple i of D_(x)·D_(y). Whenthe 8K FFT mode is applied, the last position value of sub index tablePN1 may not be applied. When the 16K FFT mode is applied, the lastposition value of sub index table PN1 is applied whereas the lastposition value of sub index table PN2 may not be applied.

The index table for the 32K FFT mode can be generated using the indextable for the 16K FFT mode and an index table obtained by reversing theindex table for the 16K FFT mode. Accordingly, the last position valueof sub index table PN1 can be used twice and the last position value ofsub index table PN2 can be used only once.

In the extension of a sub index table, extension according to v may benecessary or unnecessary according to embodiment. That is, there may bean embodiment of extending/reversing a sub index table without v.

In CP pattern generation method #1 using the pattern reversal method,the aforementioned multiplexing rule can be represented by the followingExpression. The following Expression may be an equation for generatingCP positions to be used in each FFT mode from a predetermined referenceindex table.

A CP pattern in each FFT mode can be generated according to Expression8. Here, symbols may be the same as the above-described ones. β denotesan integer closest to the NOA of the 8K FFT mode. That is, when the NOAis 6817, β may be 6816.

In CP_8K(k), CP_16K(k) and CP_32K(k), k may be respectively limited toS_(PN1)−1, S_(PN12)−1, S_(PN121)−1 and S_(PN1212)−1. Here, −1 is addedsince the last CP position value v may be excluded according tosituation, as described above. In Expression 8,

(β − PN 1(k − S_(PN 12) + 1)), (β − PN 2(k − S_(PN 121) + 1)),

in a box represents pattern reversal.

FIG. 26 illustrates the concept of configuring a reference index tablein CP pattern generation method #2 using the pattern reversal methodaccording to an embodiment of the present invention.

CP pattern generation method #2 using the pattern reversal method willnow be described.

As described above, when the reference index table is generated, thetable can be divided into sub index tables having a predetermined size.The sub index tables may include CP positions generated using differentPN generators (or different seeds).

Two sub index tables necessary in the 8K, 16K and 32K FFT modes can begenerated by two different PN generators, as described above. Two subindex tables additionally necessary in the 32K FFT mode can be generatedby reversing the pre-generated two sub index tables. However, CP patterngeneration method #2 using the pattern reversal method can generate twonecessary sub index tables by cyclic-shifting patterns and thenreversing the patterns rather than simply reversing the previouslygenerated two sub index tables. Reversing operation may precede cyclicshifting operation according to embodiment. Otherwise, simple shiftinginstead of cyclic shifting may be performed according to embodiment.

Accordingly, a CP index table in the 32K FFT mode can include a CP indextable in the 16K FFT mode. In addition, the CP index table in the 16KFFT mode can include a CP index table in the 8K FFT mode. According toan embodiment, the CP index table in the 32K FFT mode may be stored andthe CP index tables in the 8K and 16K FFT modes may beselected/extracted from the CP index table in the 32K FFT mode togenerate the CP index tables in the 8K and 16K FFT modes.

As described above, when the 16K FFT mode is supported, CP positionvalues according to PN1 and PN2 can be sequentially arranged to obtain aCP position distribution. However, according to CP pattern generationmethod #2 using the pattern reversal method, CP position valuesaccording to PN1 and PN2 can be cyclically shifted and then reversed toobtain a CP position distribution when the 32K FFT mode is supported.

According to CP pattern generation method #2 using the pattern reversalmethod, CP positions can be distributed evenly and randomly over thespectrum. In addition, the size of a necessary reference index table canbe reduced compared to the aforementioned position multiplexing method.Furthermore, memory storage capacity necessary for the receiver can bedecreased.

In CP pattern generation method #2 using the pattern reversal method,the aforementioned multiplexing rule can be represented by the followingExpression. The following Expression may be an equation for generatingCP positions to be used in each FFT mode from a predetermined referenceindex table.

A CP pattern in each FFT mode can be generated according to Expression9. Here, symbols may be the same as the above-described ones. β denotesan integer closest to the NOA of the 8K FFT mode. That is, when the NOAis 6817, β may be 6816. γ_(1/2) is a cyclic shift value.

In CP_8K(k), CP_16K(k) and CP_32K(k), k may be respectively limited toS_(PN1)−1, S_(PN12)−1, S_(PN121)−1 and S_(PN1212)−1. Here, −1 is addedsince the last CP position value v may be excluded according tosituation, as described above. In Expression 9,

mod(γ₁ + α₂ + (β − PN 1(k − S_(PN 12) + 1)), β), mod(γ₂ + α₃ + (β − PN 2(k − S_(PN 121) + 1)), β),

in a box represents pattern reversal and cyclic shifting.

The CP pattern can be generated by a method other than aforementioned CPpattern generation methods. According to other embodiments, a CP set (CPpattern) of certain FFT size can be generated from a CP set of other FFTsize, organically and dependently. In this case, a whole CP set or apart of the CP set can be base of generation process. For example, a CPset of 16K FFT mode can be generated by selecting/extracting CPpositions from a CP set of 32K FFT mode. In same manner, a CP set of 8KFFT mode can be generated by selecting/extracting CP positions from a CPset of 32K FFT mode.

According to other embodiments, CP set can include SP bearing CPpositions and/or non SP bearing CP positions. Non SP bearing CPpositions can be referred to as common CP set. SP bearing CP positionscan be referred to as additional CP set. That is, CP set can include acommon CP set and/or an additional CP set. A case that only a common CPset is included in the CP set can be referred to as normal CP mode. Acase that the CP set includes both a common CP set and an additional CPset can be referred to as extended CP mode.

Values of common CP sets can be different based on FFT size. Accordingto embodiments, the common CP set can be generated by aforementionedPattern reversal method and/or Position multiplexing method.

Values of additional CP sets can be different based on transmissionmethods, such as SISO or MIMO. In situation that additional robustnessis needed, such as mobile reception, or for any other reasons,additional CP positions can be added to the CP set, by adding anadditional CP set.

Consequently, CP insertion can be performed according to the CP set(reference index table).

FIG. 27 illustrates a method of transmitting broadcast signal accordingto an embodiment of the present invention.

The method includes encoding DP (Data Pipe) data, building at least onesignal frame, and/or modulating data by OFDM method & transmittingbroadcast signals.

In step of encoding DP data, the above described coding & modulationmodule may encode DP data in each data path. The DP can be also referredto as Physical Layer Pipe, PLP. The step of encoding DP data can includeLDPC (Low Density Parity Check) encoding, bit interleaving, mapping ontoconstellations, MIMO (Multi Input Multi Output) encoding, and/or timeinterleaving.

The step of LDPC encoding corresponds to above described LDPC encoding.The LDPC encoding can be performed on the DP data according to the coderate.

The step of bit interleaving corresponds to above-described bitinterleaving by the bit interleaver. The bit interleaving can beperformed on the LDPC encoded DP data.

The step of mapping onto constellations, corresponds to above-describedconstellation mapping by the constellation mapper. The mapping ontoconstellation can be performed on the bit interleaved DP data.

The step of MIMO encoding corresponds to above-dsecribed MIMO encodingby the MIMO encoder. The MIMO encoding can be performed by using a MIMOmatrix. The MIMO matrix can have MIMO coefficient for power imbalanceadjustment. The MIMO encoding can be performed on the mapped DP data.

The step of time interleaving corresponds to above-described timeinterleaving by the time interleaver. The time interleaving can beperformed on the MIMO encoded DP data.

In step of building at least one signal frame, the above-described framestructure module can build signal frames by arranging (or allocating)the encoded DP data.

In step of modulating data by OFDM method & transmitting broadcastsignals, the above-described waveform generation module can modulatedata in OFDM method, and transmit the broadcast signals.

In this embodiment, the step of modulating can include inserting CPs(Continual Pilots) in the built signal frame. Inserting CPs can beconducted based on a CP set. The CP set can include information aboutlocations of CPs, as described above. The CP set corresponds toaforementioned reference index table. The CP set can be defined based onFFT (Fast Fourier Transform) size.

In a method of transmitting broadcast signals according to otherembodiment of the present invention, the CP set includes a common CP setand an additional CP set. The common CP set and the additional CP setare described above. Extra CP positions can be added based on encodingscheme, such as SISO, MIMO. Or in low SNR situation, extra CP positionscan be added to secure high robustness.

In a method of transmitting broadcast signals according to anotherembodiment of the present invention, the information about locations ofCPs in the common CP set defined based on 32K FFT size includes theinformation about locations of CPs in the common CP set defined based on16K FFT size. The CP set of 32K FFT mode can include the CP set of 16KFFT mode. That is, the CP set of 32K FFT mode can include CP positionsthat can be used in the CP set of 16K FFT mode. In pattern reversalmethod, the CP set of 32K FFT mode can be generated by using the CP setof 16K FFT mode. Therefore, the CP set of 32K FFT mode can haveinformation about positions of CPs that can be also included in the CPset of 16K FFT mode. In other embodiment, the CP set of 16K FFT mode canbe extracted from the CP set of 32K FFT mode. Therefore, the CP set of32K FFT mode can have information about positions of CPs that can bealso included in the CP set of 16K FFT mode. This relationship can beestablished between a CP set of 16K FFT mode and a CP set of 8K FFTmode.

In a method of transmitting broadcast signals according to anotherembodiment of the present invention, the common CP set includesinformation about locations of non SP (Scattered Pilot) bearing CPs, andthe additional CP set includes information about locations of SP bearingCPs, as described above. The common CP set can have non SP bearing CPpositions, and the additional CP set can include SP bearing CPpositions.

In a method of transmitting broadcast signals according to anotherembodiment of the present invention, the common CP set defined based on32K FFT size includes a first sub-set, a second sub-set, a third sub-setand a fourth sub-set. The third sub-set is generated by inverting thefirst sub-set and shifting the inverted first sub-set. The fourthsub-set is generated by inverting the second sub-set and shifting thethe inverted second sub-set. The first, second, third and fourth subsetmay correspond to each subset in the CP pattern generation method #2using the pattern reversal method. By inverting and shifting a subset,other subset can be generated. CP pattern generation method #2 using thepattern reversal method is well described above.

The above-described steps can be omitted or replaced by steps executingsimilar or identical functions according to design.

FIG. 28 illustrates a method of receiving broadcast signal according toan embodiment of the present invention.

The method includes receiving broadcast signals & demodulating data byOFDM method, parsing the at least one signal frame, and/or decoding theDP data.

In step of receiving broadcast signals & demodulating data by OFDMmethod, the above-described synchronization & demodulation modulereceives broadcast signals, and demodulates data by OFDM method.

In step of parsing the at least one signal frame, the above-describedframe parsing module parses the signal frame by demapping DP data.

In step of decoding the DP data, the above-described demapping &decoding module decodes the DP data. Step of decoding the DP data caninclude time deinterleaving, MIMO (Multi Input Multi Output) decoding,demapping from constellations, bit deinterleaving, and/or LDPC (LowDensity Parity Check) decoding.

In step of time deinterleaving, the above-described time deinterleavercan conduct time deinterleaving DP data.

In step of MIMO decoding, the above-described MIMO decoder can conductMIMO decoding DP data. MIMO decoding can be conducted by using MIMOmatrix including MIMO coefficient. MIMO coefficient can be used foradjusting power imbalance.

In step of demapping from constellations, the above-describedconstellation demapper can conduct demapping. The demapping can beconducted on DP data.

In step of bit deinterleaving, the above-described bit deinterleaver canconduct bit deinterleaving.

In step of LDPC decoding. the above-described LDPC decoder (or FECdecoder) can decode DP data according to LDPC code.

In this embodiment, the step of demodulating includes step of obtainingCPs (Continual Pilots) in the signal frame. The CPs are located based ona CP set. The CP set corresponds to above-described CP set (or referenceindex table). The CP set can include information about locations of CPs.The CP set can include CP's positions. The CP set is defined based onFFT (Fast Fourier Transform) size.

In a method of receiving broadcast signals according to other embodimentof the present invention, the CP set includes a common CP set and anadditional CP set. The common CP set and the additional CP set aredescribed above. Extra CP positions can be added based on encodingscheme, such as SISO, MIMO. Or in low SNR situation, extra CP positionscan be added to secure high robustness.

In a method of receiving broadcast signals according to anotherembodiment of the present invention, the information about locations ofCPs in the common CP set defined based on 32K FFT size includes theinformation about locations of CPs in the common CP set defined based on16K FFT size. The CP set of 32K FFT mode can include the CP set of 16KFFT mode. That is, the CP set of 32K FFT mode can include CP positionsthat can be used in the CP set of 16K FFT mode. In pattern reversalmethod, the CP set of 32K FFT mode can be generated by using the CP setof 16K FFT mode. Therefore, the CP set of 32K FFT mode can haveinformation about positions of CPs that can be also included in the CPset of 16K FFT mode. In other embodiment, the CP set of 16K FFT mode canbe extracted from the CP set of 32K FFT mode. Therefore, the CP set of32K FFT mode can have information about positions of CPs that can bealso included in the CP set of 16K FFT mode. This relationship can beestablished between a CP set of 16K FFT mode and a CP set of 8K FFTmode.

In a method of receiving broadcast signals according to anotherembodiment of the present invention, the common CP set includesinformation about locations of non SP (Scattered Pilot) bearing CPs, andthe additional CP set includes information about locations of SP bearingCPs, as described above. The common CP set can have non SP bearing CPpositions, and the additional CP set can include SP bearing CPpositions.

In a method of receiving broadcast signals according to anotherembodiment of the present invention, the common CP set defined based on32K FFT size includes a first sub-set, a second sub-set, a third sub-setand a fourth sub-set. The third sub-set is generated by inverting thefirst sub-set and shifting the inverted first sub-set. The fourthsub-set is generated by inverting the second sub-set and shifting thethe inverted second sub-set. The first, second, third and fourth subsetmay correspond to each subset in the CP pattern generation method #2using the pattern reversal method. By inverting and shifting a subset,other subset can be generated. CP pattern generation method #2 using thepattern reversal method is well described above.

The above-described steps can be omitted or replaced by steps executingsimilar or identical functions according to design.

Although the description of the present invention is explained withreference to each of the accompanying drawings for clarity, it ispossible to design new embodiment(s) by merging the embodiments shown inthe accompanying drawings with each other. And, if a recording mediumreadable by a computer, in which programs for executing the embodimentsmentioned in the foregoing description are recorded, is designed innecessity of those skilled in the art, it may belong to the scope of theappended claims and their equivalents.

An apparatus and method according to the present invention may benon-limited by the configurations and methods of the embodimentsmentioned in the foregoing description. And, the embodiments mentionedin the foregoing description can be configured in a manner of beingselectively combined with one another entirely or in part to enablevarious modifications.

In addition, a method according to the present invention can beimplemented with processor-readable codes in a processor-readablerecording medium provided to a network device. The processor-readablemedium may include all kinds of recording devices capable of storingdata readable by a processor. The processor-readable medium may includeone of ROM, RAM, CD-ROM, magnetic tapes, floppy discs, optical datastorage devices, and the like for example and also include such acarrier-wave type implementation as a transmission via Internet.Furthermore, as the processor-readable recording medium is distributedto a computer system connected via network, processor-readable codes canbe saved and executed according to a distributive system.

It will be appreciated by those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

Both apparatus and method inventions are mentioned in this specificationand descriptions of both of the apparatus and method inventions may becomplementarily applicable to each other.

Various embodiments have been described in the best mode for carryingout the invention.

The present invention has industrial applicability in broadcasting andcommunication field.

1-20. (canceled)
 21. A method of transmitting broadcast signals, the method including: LDPC (Low Density Parity Check) encoding PLP data; bit interleaving the LDPC encoded PLP data; mapping the bit interleaved PLP data onto constellations; time interleaving the mapped PLP data; building at least one signal frame by arranging the time interleaved PLP data; inserting CPs (Continual Pilots) in the built signal frame; modulating data in the built signal frame by OFDM (Orthogonal Frequency Division Multiplexing) method; and transmitting the broadcast signals having the modulated data, wherein the inserted CPs include a first subset and a second subset, and wherein a location of a CP in the second subset is obtained by applying reversing operation and shifting operation to a location of a CP in the first subset.
 22. The method of claim 21, wherein the first subset includes reference indices of the CPs.
 23. The method of claim 21, wherein locations of CPs defined for 32K FFT size includes locations of CPs defined for 16K FFT size.
 24. The method of claim 21, wherein the locations of the CPs are locations of non SP (Scattered Pilot) bearing CPs, and wherein SP bearing CPs are further inserted in the built signal frame.
 25. The method of claim 21, wherein the reversing operation precedes the shifting operation when the second subset is generated.
 26. A method of receiving broadcast signals, the method including: receiving the broadcast signals having at least one signal frame and demodulating data in the at least one signal frame by OFDM (Orthogonal Frequency Division Multiplexing) method; parsing the at least one signal frame including PLP (Physical Layer Pipe) data; time deinterleaving the PLP data; demapping the time deinterleaved PLP data; bit deinterleaving the demapped PLP data; and LDPC (Low Density Parity Check) decoding the bit deinterleaved PLP data, wherein CPs (Continual Pilots) are included in the at least one signal frame, wherein the CPs include a first subset and a second subset, and wherein a location of a CP in the second subset is obtained by applying reversing operation and shifting operation to a location of a CP in the first subset.
 27. The method of claim 26, wherein the first subset includes reference indices of the CPs.
 28. The method of claim 26, wherein locations of CPs defined for 32K FFT size includes locations of CPs defined for 16K FFT size.
 29. The method of claim 26, wherein the locations of the CPs are locations of non SP (Scattered Pilot) bearing CPs, and wherein SP bearing CPs are further inserted in the built signal frame.
 30. The method of claim 26, wherein the reversing operation precedes the shifting operation when the second subset is generated.
 31. An apparatus for transmitting broadcast signals, the apparatus including: a LDPC (Low Density Parity Check) encoder to LDPC encode PLP data; a bit interleaver to bit interleave the LDPC encoded PLP data; a mapper to map the bit interleaved PLP data onto constellations; a time interleaver to time interleave the mapped PLP data; a frame builder to build at least one signal frame by arranging the time interleaved PLP data; a pilot inserter to insert CPs (Continual Pilots) in the built signal frame; a modulator to modulate data in the built signal frame by OFDM (Orthogonal Frequency Division Multiplexing) method; and a transmitter to transmit the broadcast signals having the modulated data, wherein the inserted CPs include a first subset and a second subset, and wherein a location of a CP in the second subset is obtained by applying reversing operation and shifting operation to a location of a CP in the first subset.
 32. The apparatus of claim 31, wherein the first subset includes reference indices of the CPs.
 33. The apparatus of claim 31, wherein locations of CPs defined for 32K FFT size includes locations of CPs defined for 16K FFT size.
 34. The apparatus of claim 31, wherein the locations of the CPs are locations of non SP (Scattered Pilot) bearing CPs, and wherein SP bearing CPs are further inserted in the built signal frame.
 35. The apparatus of claim 31, wherein the reversing operation precedes the shifting operation when the second subset is generated.
 36. An apparatus for receiving broadcast signals, the apparatus including: a receiver to receive the broadcast signals having at least one signal frame; a demodulator to demodulate data in the at least one signal frame by OFDM method; a frame parser to parse the at least one signal frame including PLP (Physical Layer Pipe) data; a time deinterleaver to time deinterleave the PLP data; a demapper to demap the time deinterleaved PLP data; a bit deinterleaver to bit deinterleave the demapped PLP data; and a LDPC (Low Density Parity Check) decode to LDPC decode the bit deinterleaved PLP data, wherein CPs (Continual Pilots) are included in the at least one signal frame, wherein the CPs include a first subset and a second subset, and wherein a location of a CP in the second subset is obtained by applying reversing operation and shifting operation to a location of a CP in the first subset.
 37. The apparatus of claim 36, wherein the first subset includes reference indices of the CPs.
 38. The apparatus of claim 36, wherein locations of CPs defined for 32K FFT size includes locations of CPs defined for 16K FFT size.
 39. The apparatus of claim 36, wherein the locations of the CPs are locations of non SP (Scattered Pilot) bearing CPs, and wherein SP bearing CPs are further inserted in the built signal frame.
 40. The apparatus of claim 36, wherein the reversing operation precedes the shifting operation when the second subset is generated. 